Add support for Riak CS Control

Adding Riak CS Control support to this project consists of the following:

- [ ] 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
- [ ] The creation of a [riak-cs-control](https://github.com/hectcastro/riak-cs-control-chef-cookbook) cookbook

This pull request can be tested as is. After the `riak-cs-create-admin-user` PR is merged, references to it in the `Berksfile` need to be updated so that they point to the `master` branch and not `riak-cs-control`.