Move from jeweler to bundler for gem packaging and add rspec for testing

* new lib/casein/version.rb file which contains VERSION
* updated gemspec to include dependencies for testing
* added spec/rails_test_app for testing
* added a simple helper spec that passes
* new spec task
* dumped test tasks
* dumped jewelers tasks
remove accidentally merged color field stuff
dump test directory (in favor of spec)
Use new Casein::VERSION in helpers

* update CaseinHelper version related methods to use the Casein::VERSION
* add a couple more specs around that
Add color, search and telephone fields with tests

* new casein field helpers for search, color, telephone
* added model in test app that has lots of fields
* add view helper in spec/support
* installed casein into the test_app