Change ruby version to 2.1.0 and rails' to 4.1.0.beta

Also removed unecessary dependencies, and added spring as environment
loader.
Fix travis ruby version
Fix Gemfile.lock
Remove traces of shoulda
Merge pull request #2 from gc-corp/rails41-ruby21

Change ruby version to 2.1.0 and rails' to 4.1.0.beta