Add test targeting bugzilla bug 1112802

Add a test which checks that issuing an HTTP GET to the "/rhsm" path results in
a response with the following properties:

* It has an HTTP 200 status code.
* It has an application/json content-type
* When the JSON is decoded, the response is a list.
Merge pull request #1270 from Ichimonji10/bz-1112802

Add test targeting bugzilla bug #1112802