Fixes login_from_token

Login from token should halt execution if the token is not present or
its invalid
Enables /api/v1/projects/:id/builds.json

This endpoint allows to build the current HEAD of the project
Adds the token to top bar
Adds task to populate User#single_access_token
Downgrade 1 major version of Rack
Adds tmp folder to git repo but ignore everything inside

This is required because one of the tests relies on the existance of
this folder
Rollback gems update