Support earlier Chef versions on not-Windows
Use the ChefDK install script in Travis
Merge pull request #22 from RoboticCheese/roboticcheese/support-chef-pre-11.12

Support chef pre 11.12
Add dependency on fog
Remove sudo from Travis config
Use Travis ENV variables and new DO driver
Merge pull request #23 from RoboticCheese/roboticcheese/fix-build

Use Travis ENV variables and new DO driver
Merge branch 'master' into chefdk_primary