Update to Engine Setup Readme
Add Katello namespace to Authorization::Provider

Fixes an error that occurs when using katello_api at
https://github.com/Katello/katello_api/pull/13 to generate v2 API
documentation for the changes I made to the ProductController in
https://github.com/Katello/katello/pull/3479
allow user requests to modify enabled repos

(in addition to rhsm) this allows us to more easily simulate
a system via trebuchet
fixing some instances of ::Pool

need to look in Katello::

Also, fixing an environments controller index action,
as it was passing query_params to KTEnvironment.where()
and api_version was causing issues
Merge pull request #3489 from mkelley33/katello-namespace-provider

Add Katello namespace to Authorization::Provider
Merge pull request #3470 from mptap/readme_update

Update to Engine Setup Readme
Merge pull request #3492 from jlsherrill/enable_repos

allow user requests to modify enabled repos
Merge pull request #3491 from jlsherrill/pool

fixing some instances of ::Pool