diff --git a/front-end/package-lock.json b/front-end/package-lock.json
index c26f64d..d681cea 100644
--- a/front-end/package-lock.json
+++ b/front-end/package-lock.json
@@ -474,6 +474,7 @@
       "resolved": "https://registry.npmjs.org/are-we-there-yet/-/are-we-there-yet-1.1.4.tgz",
       "integrity": "sha1-u13KOCu5TwXhUZQ3PRb9O6HKEQ0=",
       "dev": true,
+      "optional": true,
       "requires": {
         "delegates": "1.0.0",
         "readable-stream": "2.3.6"
@@ -1677,7 +1678,8 @@
       "version": "1.1.0",
       "resolved": "https://registry.npmjs.org/console-control-strings/-/console-control-strings-1.1.0.tgz",
       "integrity": "sha1-PXz0Rk22RG6mRL9LOVB/mFEAjo4=",
-      "dev": true
+      "dev": true,
+      "optional": true
     },
     "constants-browserify": {
       "version": "1.0.0",
@@ -2147,7 +2149,8 @@
       "version": "1.0.0",
       "resolved": "https://registry.npmjs.org/delegates/-/delegates-1.0.0.tgz",
       "integrity": "sha1-hMbhWbgZBP3KWaDvRM2HDTElD5o=",
-      "dev": true
+      "dev": true,
+      "optional": true
     },
     "denodeify": {
       "version": "1.2.1",
@@ -2836,45 +2839,45 @@
     "express": {
       "version": "4.16.3",
       "resolved": "https://registry.npmjs.org/express/-/express-4.16.3.tgz",
-      "integrity": "sha1-avilAjUNsyRuzEvs9rWjTSL37VM=",
+      "integrity": "sha512-CDaOBMB9knI6vx9SpIxEMOJ6VBbC2U/tYNILs0qv1YOZc15K9U2EcF06v10F0JX6IYcWnKYZJwIDJspEHLvUaQ==",
       "dev": true,
       "requires": {
-        "accepts": "1.3.5",
+        "accepts": "~1.3.5",
         "array-flatten": "1.1.1",
         "body-parser": "1.18.2",
         "content-disposition": "0.5.2",
-        "content-type": "1.0.4",
+        "content-type": "~1.0.4",
         "cookie": "0.3.1",
         "cookie-signature": "1.0.6",
         "debug": "2.6.9",
-        "depd": "1.1.2",
-        "encodeurl": "1.0.2",
-        "escape-html": "1.0.3",
-        "etag": "1.8.1",
+        "depd": "~1.1.2",
+        "encodeurl": "~1.0.2",
+        "escape-html": "~1.0.3",
+        "etag": "~1.8.1",
         "finalhandler": "1.1.1",
         "fresh": "0.5.2",
         "merge-descriptors": "1.0.1",
-        "methods": "1.1.2",
-        "on-finished": "2.3.0",
-        "parseurl": "1.3.2",
+        "methods": "~1.1.2",
+        "on-finished": "~2.3.0",
+        "parseurl": "~1.3.2",
         "path-to-regexp": "0.1.7",
-        "proxy-addr": "2.0.3",
+        "proxy-addr": "~2.0.3",
         "qs": "6.5.1",
-        "range-parser": "1.2.0",
+        "range-parser": "~1.2.0",
         "safe-buffer": "5.1.1",
         "send": "0.16.2",
         "serve-static": "1.13.2",
         "setprototypeof": "1.1.0",
-        "statuses": "1.4.0",
-        "type-is": "1.6.16",
+        "statuses": "~1.4.0",
+        "type-is": "~1.6.16",
         "utils-merge": "1.0.1",
-        "vary": "1.1.2"
+        "vary": "~1.1.2"
       },
       "dependencies": {
         "array-flatten": {
           "version": "1.1.1",
           "resolved": "https://registry.npmjs.org/array-flatten/-/array-flatten-1.1.1.tgz",
-          "integrity": "sha1-ml9pkFGx5wczKPKgCJaLZOopVdI=",
+          "integrity": "sha512-PCVAQswWemu6UdxsDFFX/+gVeYqKAod3D3UVm91jHwynguOwAvYPhx8nNlM++NqRcK6CxxpUafjmhIdKiHibqg==",
           "dev": true
         },
         "qs": {
@@ -3210,7 +3213,8 @@
         "ansi-regex": {
           "version": "2.1.1",
           "bundled": true,
-          "dev": true
+          "dev": true,
+          "optional": true
         },
         "aproba": {
           "version": "1.1.1",
@@ -3261,7 +3265,8 @@
         "balanced-match": {
           "version": "0.4.2",
           "bundled": true,
-          "dev": true
+          "dev": true,
+          "optional": true
         },
         "bcrypt-pbkdf": {
           "version": "1.0.1",
@@ -3276,6 +3281,7 @@
           "version": "0.0.9",
           "bundled": true,
           "dev": true,
+          "optional": true,
           "requires": {
             "inherits": "2.0.3"
           }
@@ -3284,6 +3290,7 @@
           "version": "2.10.1",
           "bundled": true,
           "dev": true,
+          "optional": true,
           "requires": {
             "hoek": "2.16.3"
           }
@@ -3292,6 +3299,7 @@
           "version": "1.1.7",
           "bundled": true,
           "dev": true,
+          "optional": true,
           "requires": {
             "balanced-match": "0.4.2",
             "concat-map": "0.0.1"
@@ -3300,7 +3308,8 @@
         "buffer-shims": {
           "version": "1.0.0",
           "bundled": true,
-          "dev": true
+          "dev": true,
+          "optional": true
         },
         "caseless": {
           "version": "0.12.0",
@@ -3317,12 +3326,14 @@
         "code-point-at": {
           "version": "1.1.0",
           "bundled": true,
-          "dev": true
+          "dev": true,
+          "optional": true
         },
         "combined-stream": {
           "version": "1.0.5",
           "bundled": true,
           "dev": true,
+          "optional": true,
           "requires": {
             "delayed-stream": "1.0.0"
           }
@@ -3330,22 +3341,26 @@
         "concat-map": {
           "version": "0.0.1",
           "bundled": true,
-          "dev": true
+          "dev": true,
+          "optional": true
         },
         "console-control-strings": {
           "version": "1.1.0",
           "bundled": true,
-          "dev": true
+          "dev": true,
+          "optional": true
         },
         "core-util-is": {
           "version": "1.0.2",
           "bundled": true,
-          "dev": true
+          "dev": true,
+          "optional": true
         },
         "cryptiles": {
           "version": "2.0.5",
           "bundled": true,
           "dev": true,
+          "optional": true,
           "requires": {
             "boom": "2.10.1"
           }
@@ -3385,7 +3400,8 @@
         "delayed-stream": {
           "version": "1.0.0",
           "bundled": true,
-          "dev": true
+          "dev": true,
+          "optional": true
         },
         "delegates": {
           "version": "1.0.0",
@@ -3417,7 +3433,8 @@
         "extsprintf": {
           "version": "1.0.2",
           "bundled": true,
-          "dev": true
+          "dev": true,
+          "optional": true
         },
         "forever-agent": {
           "version": "0.6.1",
@@ -3439,12 +3456,14 @@
         "fs.realpath": {
           "version": "1.0.0",
           "bundled": true,
-          "dev": true
+          "dev": true,
+          "optional": true
         },
         "fstream": {
           "version": "1.0.11",
           "bundled": true,
           "dev": true,
+          "optional": true,
           "requires": {
             "graceful-fs": "4.1.11",
             "inherits": "2.0.3",
@@ -3500,6 +3519,7 @@
           "version": "7.1.2",
           "bundled": true,
           "dev": true,
+          "optional": true,
           "requires": {
             "fs.realpath": "1.0.0",
             "inflight": "1.0.6",
@@ -3512,7 +3532,8 @@
         "graceful-fs": {
           "version": "4.1.11",
           "bundled": true,
-          "dev": true
+          "dev": true,
+          "optional": true
         },
         "har-schema": {
           "version": "1.0.5",
@@ -3540,6 +3561,7 @@
           "version": "3.1.3",
           "bundled": true,
           "dev": true,
+          "optional": true,
           "requires": {
             "boom": "2.10.1",
             "cryptiles": "2.0.5",
@@ -3550,7 +3572,8 @@
         "hoek": {
           "version": "2.16.3",
           "bundled": true,
-          "dev": true
+          "dev": true,
+          "optional": true
         },
         "http-signature": {
           "version": "1.1.1",
@@ -3567,6 +3590,7 @@
           "version": "1.0.6",
           "bundled": true,
           "dev": true,
+          "optional": true,
           "requires": {
             "once": "1.4.0",
             "wrappy": "1.0.2"
@@ -3575,7 +3599,8 @@
         "inherits": {
           "version": "2.0.3",
           "bundled": true,
-          "dev": true
+          "dev": true,
+          "optional": true
         },
         "ini": {
           "version": "1.3.4",
@@ -3587,6 +3612,7 @@
           "version": "1.0.0",
           "bundled": true,
           "dev": true,
+          "optional": true,
           "requires": {
             "number-is-nan": "1.0.1"
           }
@@ -3600,7 +3626,8 @@
         "isarray": {
           "version": "1.0.0",
           "bundled": true,
-          "dev": true
+          "dev": true,
+          "optional": true
         },
         "isstream": {
           "version": "0.1.2",
@@ -3673,12 +3700,14 @@
         "mime-db": {
           "version": "1.27.0",
           "bundled": true,
-          "dev": true
+          "dev": true,
+          "optional": true
         },
         "mime-types": {
           "version": "2.1.15",
           "bundled": true,
           "dev": true,
+          "optional": true,
           "requires": {
             "mime-db": "1.27.0"
           }
@@ -3687,6 +3716,7 @@
           "version": "3.0.4",
           "bundled": true,
           "dev": true,
+          "optional": true,
           "requires": {
             "brace-expansion": "1.1.7"
           }
@@ -3694,12 +3724,14 @@
         "minimist": {
           "version": "0.0.8",
           "bundled": true,
-          "dev": true
+          "dev": true,
+          "optional": true
         },
         "mkdirp": {
           "version": "0.5.1",
           "bundled": true,
           "dev": true,
+          "optional": true,
           "requires": {
             "minimist": "0.0.8"
           }
@@ -3754,7 +3786,8 @@
         "number-is-nan": {
           "version": "1.0.1",
           "bundled": true,
-          "dev": true
+          "dev": true,
+          "optional": true
         },
         "oauth-sign": {
           "version": "0.8.2",
@@ -3772,6 +3805,7 @@
           "version": "1.4.0",
           "bundled": true,
           "dev": true,
+          "optional": true,
           "requires": {
             "wrappy": "1.0.2"
           }
@@ -3801,7 +3835,8 @@
         "path-is-absolute": {
           "version": "1.0.1",
           "bundled": true,
-          "dev": true
+          "dev": true,
+          "optional": true
         },
         "performance-now": {
           "version": "0.2.0",
@@ -3812,7 +3847,8 @@
         "process-nextick-args": {
           "version": "1.0.7",
           "bundled": true,
-          "dev": true
+          "dev": true,
+          "optional": true
         },
         "punycode": {
           "version": "1.4.1",
@@ -3850,6 +3886,7 @@
           "version": "2.2.9",
           "bundled": true,
           "dev": true,
+          "optional": true,
           "requires": {
             "buffer-shims": "1.0.0",
             "core-util-is": "1.0.2",
@@ -3894,6 +3931,7 @@
           "version": "2.6.1",
           "bundled": true,
           "dev": true,
+          "optional": true,
           "requires": {
             "glob": "7.1.2"
           }
@@ -3901,7 +3939,8 @@
         "safe-buffer": {
           "version": "5.0.1",
           "bundled": true,
-          "dev": true
+          "dev": true,
+          "optional": true
         },
         "semver": {
           "version": "5.3.0",
@@ -3925,6 +3964,7 @@
           "version": "1.0.9",
           "bundled": true,
           "dev": true,
+          "optional": true,
           "requires": {
             "hoek": "2.16.3"
           }
@@ -3958,6 +3998,7 @@
           "version": "1.0.2",
           "bundled": true,
           "dev": true,
+          "optional": true,
           "requires": {
             "code-point-at": "1.1.0",
             "is-fullwidth-code-point": "1.0.0",
@@ -3968,6 +4009,7 @@
           "version": "1.0.1",
           "bundled": true,
           "dev": true,
+          "optional": true,
           "requires": {
             "safe-buffer": "5.0.1"
           }
@@ -3982,6 +4024,7 @@
           "version": "3.0.1",
           "bundled": true,
           "dev": true,
+          "optional": true,
           "requires": {
             "ansi-regex": "2.1.1"
           }
@@ -3996,6 +4039,7 @@
           "version": "2.2.1",
           "bundled": true,
           "dev": true,
+          "optional": true,
           "requires": {
             "block-stream": "0.0.9",
             "fstream": "1.0.11",
@@ -4051,7 +4095,8 @@
         "util-deprecate": {
           "version": "1.0.2",
           "bundled": true,
-          "dev": true
+          "dev": true,
+          "optional": true
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         "uuid": {
           "version": "3.0.1",
@@ -4080,7 +4125,8 @@
         "wrappy": {
           "version": "1.0.2",
           "bundled": true,
-          "dev": true
+          "dev": true,
+          "optional": true
         }
       }
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@@ -4089,6 +4135,7 @@
       "resolved": "https://registry.npmjs.org/fstream/-/fstream-1.0.11.tgz",
       "integrity": "sha1-XB+x8RdHcRTwYyoOtLcbPLD9MXE=",
       "dev": true,
+      "optional": true,
       "requires": {
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         "inherits": "2.0.3",
@@ -4107,6 +4154,7 @@
       "resolved": "https://registry.npmjs.org/gauge/-/gauge-2.7.4.tgz",
       "integrity": "sha1-LANAXHU4w51+s3sxcCLjJfsBi/c=",
       "dev": true,
+      "optional": true,
       "requires": {
         "aproba": "1.2.0",
         "console-control-strings": "1.1.0",
@@ -4433,7 +4481,8 @@
       "version": "2.0.1",
       "resolved": "https://registry.npmjs.org/has-unicode/-/has-unicode-2.0.1.tgz",
       "integrity": "sha1-4Ob+aijPUROIVeCG0Wkedx3iqLk=",
-      "dev": true
+      "dev": true,
+      "optional": true
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     "has-value": {
       "version": "1.0.0",
@@ -6384,7 +6433,8 @@
           "version": "2.2.1",
           "resolved": "https://registry.npmjs.org/ansi-styles/-/ansi-styles-2.2.1.tgz",
           "integrity": "sha1-tDLdM1i2NM914eRmQ2gkBTPB3b4=",
-          "dev": true
+          "dev": true,
+          "optional": true
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         "caseless": {
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@@ -6398,6 +6448,7 @@
           "resolved": "https://registry.npmjs.org/chalk/-/chalk-1.1.3.tgz",
           "integrity": "sha1-qBFcVeSnAv5NFQq9OHKCKn4J/Jg=",
           "dev": true,
+          "optional": true,
           "requires": {
             "ansi-styles": "2.2.1",
             "escape-string-regexp": "1.0.5",
@@ -6459,7 +6510,8 @@
           "version": "2.0.0",
           "resolved": "https://registry.npmjs.org/supports-color/-/supports-color-2.0.0.tgz",
           "integrity": "sha1-U10EXOa2Nj+kARcIRimZXp3zJMc=",
-          "dev": true
+          "dev": true,
+          "optional": true
         },
         "tunnel-agent": {
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@@ -6521,6 +6573,7 @@
       "resolved": "https://registry.npmjs.org/npmlog/-/npmlog-4.1.2.tgz",
       "integrity": "sha512-2uUqazuKlTaSI/dC8AzicUck7+IrEaOnN/e0jd3Xtt1KcGpwx30v50mL7oPyr/h9bL3E4aZccVwpwP+5W9Vjkg==",
       "dev": true,
+      "optional": true,
       "requires": {
         "are-we-there-yet": "1.1.4",
         "console-control-strings": "1.1.0",
@@ -10921,6 +10974,7 @@
       "resolved": "https://registry.npmjs.org/wide-align/-/wide-align-1.1.2.tgz",
       "integrity": "sha512-ijDLlyQ7s6x1JgCLur53osjm/UXUYD9+0PbYKrBsYisYXzCxN+HC3mYDNy/dWdmf3AwqwU3CXwDCvsNgGK1S0w==",
       "dev": true,
+      "optional": true,
       "requires": {
         "string-width": "1.0.2"
       }