Merge pull request #82 from fsmanuel/master

adds RocketPants::TestHelper::ResponseHelper to ActionDispatch::TestResponse
Clarifying error message

Always see these in log and have to look twice — clarifying that an exception is raised, not that a rendering error has occurred. :)
Fix typo in README.md
Merge pull request #86 from bwr/readme-fix

Fix typo in README.md
Merge pull request #84 from mbhnyc/master

Clarifying error message
Fix repo location, copyright.