Adds serverspec tests

ServerSpec is an RSpec extension that enables us to verify the state
of the machine once the Chef run completes. This commit adds tests
to verify that the docker service is running and that all of our containers
are listening on their expected ports.
Merge pull request #109 from opdemand/serverspec

Adds serverspec tests
Add ChefSpec/RSpec skeletons and hook up to rake
Add test coverage calculation
Set default platform/version for Runner
Flesh out controller and default specs
Remove hacky check for gem removal/installation
Add ChefSpec matchers for docker
Flesh out builder spec
Add spec matchers, fix tests
Flesh out remaining specs
Fixes all bugs! All tests run
Remove matchers that were updated in other cookbooks
Fix rubocop
Enable unit tests on Travis
Use berkshelf in both integration and test suites
Updates language for default spec
Fix rubocop
Removes 'service: command not found' errors when testing on non-Ubuntu
Fix rubocop