Gherkin removal

Removed the gherkin gem from direct usage and replaced it with
the repository modeling capabilities of cucumber_analytics.
Mutability fix.

Got repo duplication working so that the original is not mutated.
Removing dead code

Removed a couple of private methods that aren't used anymore.
Test framework update.

Added more support for RSpec and Cucumber tests, including code
coverage and rake tasks.
Gemspec update.

Added gem dependencies to the gemspec instead of having them in the
Gemfile.
No longer tracking file.

Stopped tracking Gemfile.lock.
Ignoring file.

Added Gemfile.lock to .gitignore so it does not get picked up again
by Git.
Merge branch 'ca_engine' into cm_engine