DRY up use of redhat_provider with @provider instead
Merge pull request #3466 from mkelley33/dry-up-subscriptions

DRY up use of redhat_provider with @provider instead
Update README.md

We don't need to run bundle, rake, rails s etc. from the katello checkout.

They should only be run from the foreman checkout as katello is just an engine/gem being included in it.

<From a discussion on irc with bbuckingham>