Removes the Gemfile.lock from source control

See also:
  * http://yehudakatz.com/2010/12/16/clarifying-the-roles-of-the-gemspec-and-gemfile/
Ignores vendored gems installed by Bundler

This covers the basic rbenv + Bundler workflow
Uses the RAIL_ENV environment to setup CASinoCore during spec runs

Always using the ENV variable ensures consistency across the code base.
Organizes various spec run configurations into separate support files

Each gem that requires configuration for the spec run gets its own spec/support file.

This keeps things short, succinct, and on-topic
Adds some RSpec fu for focused spec runs

Just tag a spec with `:focus` to only run that particular spec or group of specs
Uses in-memory SQLite server

Not only should this improve the speed of spec runs, but it allows all
specs to pass right out of the box. This should make it easier for
contributors to get the project up and running.

A simple `bundle install && rspec` should be all that is necessary now.