Use strainer to isolate and test individual cookbooks

Included:
- Add strainer gem
- Update test-related gems
- Add Strainer file
- Remove run_tests.bash
- Update .gitignore
- Update README file
- Add tailor (ruby style check)

Partial fix for bug 1188345

Change-Id: Iae92a999cdfe230151795fcab5b597faa958274a