Add rspec, rails and minitest modes (delay speed)
Add delay and boost fn's for rspec and minitest

* Also rewrite prompt based on type of test: "bundle exec rspec spec/"
  for rails, "rspec spec/" for rspec, and "rake test" for minitest
Remove comment

* Unimplemented feature
Merge pull request #1 from dbrady/master

Add 'rails', 'rspec' and 'minitest' modes