Imports
- github.com/Sirupsen/logrus
- github.com/alligrader/gradebook-backend/util
- github.com/gorilla/mux
- github.com/gorilla/sessions
- github.com/markbates/goth
- github.com/markbates/goth/gothic
- github.com/markbates/goth/providers/github
- github.com/spf13/viper
- golang.org/x/crypto/bcrypt