Explicitely ask for ::Rails

I was experiencing a bug where rails was not loaded, and I was getting
an error about being unable to find Spring::Application::Rails, this
will remove that ambiguity for anyone else.

Change-Id: I017a596b5b606d7bc6913f30068a85df4a4948f8
Merge pull request #148 from cbrunsdon/rails_namespace

Explicitely ask for ::Rails