Companion changes required for integration with my CASinoCore/CASino Pull Request

The following is a set of changes to CASinoApp that are required for integration with my CASinoCore Pull Request (rbCAS/CASinoCore#12) and my CASino Pull Request (rbCAS/CASino#17)

This really just formally installs the CASino Railtie into the barebones Rails application. That means that the required migrations are commited as is the `schema.rb` file. The Rails application now fully owns the models and database interaction required for a fully functional CAS server as powered by CASino.

**Note:** Before merging, I'll need to revert a change in the Gemfile so that it no longer points to my branch.