1. Added robottelo tests for run_only_on decorator
2. Optimized the code with the fixes after review comments
Port "old" API tests for content views

Make module `test_contentview_v2` accomplish most of what module
`test_contentview` formerly accomplished. Module `test_contentview` is still in
place:

* Not all tests in that module have been implemented, so they are untouched.
* Some tests in this module do not test content views, so they should be ported
  into somewhere other than `test_contentview_v2`.
Merge pull request #1372 from Ichimonji10/test-contentview-v2

Port "old" API tests for content views
Merge pull request #1385 from sthirugn/decoratortest

Added robottelo tests for run_only_on decorator
Make this work on RHEL6
Merge pull request #1388 from jhutar/master

Make this work on RHEL6
Port old API tests for products

Make module `test_product_v2` accomplish the same goals as module
`test_product`. Remove the latter module and update the API documentation
accordingly.