`npm WARN co-mocha@1.2.0 requires a peer of mocha@>=1.18 <4 but none was installed.
chenyibindeMacBook-Air:nowechat benz$ npm install tencentyoutuyun --save
nowechat@1.0.0 /Users/benz/nowechat
└── tencentyoutuyun@1.0.0
npm WARN co-mocha@1.2.0 requires a peer of mocha@>=1.18 <4 but none was installed.
chenyibindeMacBook-Air:nowechat benz$
`
`npm WARN co-mocha@1.2.0 requires a peer of mocha@>=1.18 <4 but none was installed.
chenyibindeMacBook-Air:nowechat benz$ npm install tencentyoutuyun --save
nowechat@1.0.0 /Users/benz/nowechat
└── tencentyoutuyun@1.0.0
npm WARN co-mocha@1.2.0 requires a peer of mocha@>=1.18 <4 but none was installed.
chenyibindeMacBook-Air:nowechat benz$
`