Add Test Kitchen, ChefSpec, RuboCop, and Foodcritic on Travis CI

Signed-off-by: Seth Vargo <sethvargo@gmail.com>
Add Travis CI status badge to README [ci skip]
Use Berkshelf to instal dependencies on Travis
Version bump to v1.6.0
Version bump to v1.6.1
Update CHANGELOG.md
Merged latest opscode master