Add support for Riak CS Control

Adding Riak CS Control support to this project consists of the following:

- [x] A merge of the [pull request](https://github.com/hectcastro/chef-riak-cs-create-admin-user/pull/1) against the [riak-cs-create-admin-user](https://github.com/hectcastro/chef-riak-cs-create-admin-user) cookbook
- [x] A merge of the [pull request](https://github.com/basho/riak-cs-chef-cookbook/pull/15) against the [riak-cs](https://github.com/basho/riak-cs-chef-cookbook) cookbook

This pull request can be tested as is. After the PRs are merged, references to `riak-cs-control` branches in the `Berksfile` need to be removed.