Upgrade request dependency version

[mlingner]

The request version being used right now is vulnerable to the issue discussed here: https://snyk.io/vuln/npm:request:20160119. It should be updated to 2.69.x. Thanks!

[tobiasc]

This issue is increasingly relevant, since the current version of request@2.67.x has a further vulnerability from it's tough-cookie dependency (https://nodesecurity.io/advisories/130, fixed in request@2.74.x).

This PR seems to fix it: #60