Use the most recent version of Sinatra

Without this patch an older version of sinatra was locked into place.
During debugging I went ahead and updated the version of Sinatra.  This
may or may not be supported by Heroku's cedar stack.
Update watchr rake task

Without this patch the watchr rake task isn't up to date with the
organization of the codebase.  This patch makes `bundle exec rake
watchr` useful again.
Fix spec test failures

Without this patch the spec tests have been failing due to the
reorganization of the code.  This patch addresses the problem by
updating all of the spec tests.

The return code from 204 with JSON content as a behavior has also been
patched since Rack forces no body to exist if 204 is returned as a
status code.  Instead we return 200 with the JSON message.
Add .rspec to gitignore

So I can add --fail-fast for watchr and quick refactors.