Rename tmpmodules_dir to tmp_modules_dir
Refactor all tmp sandbox paths into helper methods
Add support for testing roles!

 - Calculate default playbook path to enable embedded wrapper/test-harness playbooks for testing roles

 - Detect role name using current working directory if we are in a role dir
Merge pull request #3 from trinitronx/add-support-for-testing-roles

Add support for testing roles