Refactor Sessions Controller - users

Refactor to user model: 
`user = User.find_or_create_by(uid: auth["id"])
    user.username = auth["login"]
    user.uid = auth["id"]
    user.name = auth["name"]
    user.location = auth["location"]
    user.email = auth["email"]
    user.token = token
    user.save`