CD-126 Make strider links public

Make strider not check for authentication, this makes the shared links we get on our git commit status and hipchat notifications public (still require them to be logged in to strider though).   @vasili-zolotov 

Also fix an issue where when I make an unauthenticated API call for GET /api/job/:id, we get the following callstack:

TypeError: object is not a function
    at Promise.gotRepo (/home/ubuntu/src/strider/routes/api/jobs.js:138:19)
    at Promise.<anonymous> (/home/ubuntu/src/strider/node_modules/mongoose/node_modules/mpromise/lib/promise.js:162:8)
    at Promise.EventEmitter.emit (events.js:95:17)
    at Promise.emit (/home/ubuntu/src/strider/node_modules/mongoose/node_modules/mpromise/lib/promise.js:79:38)
    at Promise.fulfill (/home/ubuntu/src/strider/node_modules/mongoose/node_modules/mpromise/lib/promise.js:92:20)
    at /home/ubuntu/src/strider/node_modules/mongoose/lib/query.js:1794:30
    at /home/ubuntu/src/strider/node_modules/mongoose/lib/utils.js:414:16
    at /home/ubuntu/src/strider/node_modules/mongoose/node_modules/mongodb/lib/mongodb/collection.js:953:5
    at /home/ubuntu/src/strider/node_modules/mongoose/node_modules/mongodb/lib/mongodb/cursor.js:683:35
    at Cursor.close (/home/ubuntu/src/strider/node_modules/mongoose/node_modules/mongodb/lib/mongodb/cursor.js:903:5)