[COOK-2877] - remove test cookbook

Testing specific configurations will be handled by "suites".

Hopefully w/ COOK-2783, we won't need all the module specific tests anyway.
[COOK-2877] - update test kitchen support for 1.0

* Remove Gemfile (not needed as test-kitchen uses vagrant 1.1+)
* Convert Kitchenfile to .kitchen.yml, testing essential recipes only
  at this time
* Update ignores
* Add berksfile
[COOK-2877] - depend on the runit cookbook

Runit is the default init style for debian/ubuntu systems, so we need
to specify a dependency on it, otherwise, e.g., chef-solo won't load
the resources/providers and the runit_service will fail in the source
recipe. While one could use the init init_style attribute value, this
doesn't "just work" for most users.
Merge branch 'COOK-2877'