Use RSpec configuration in every spec
Reorganize and prune Cucumber features

The intent is to speed up the Cucumber suite while retaining sufficient
feature coverage.

Before: 66 scenarios, 319 steps, ~ 5 minutes
After:  39 scenarios, 188 steps, ~ 3 minutes
Tighten up source documentation
Update project badges

Add a badge for the current RubyGems release and update the Code Climate
badge to display the project's current GPA.