Merge pull request #41 from loz/master

Improves Code Structure
made rspec matchers public
Merge pull request #42 from Sage/rspec_matchers

made rspec matchers public
adds support for composite tasks to run_command matcher
Merge pull request #43 from Sage/rspec_matchers

adds support for composite tasks to run_command matcher
fixes clean bundler env task to use bundler's own implementation
Merge pull request #44 from Sage/clean_bundler_env-rvm_fix

fixes clean bundler env task to use bundler's own implementation