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
Convert and delete some old API tests

Remove the following modules:

1. `test_computeresource`
2. `test_configtemplate`
3. `test_domain`
4. `test_environments`

The first three contained no working tests and no interesting test stubs. The
existing test stubs were for goals such as creating or deleting an entity. Given
that all four relevant entities are already tested in module
`test_multiple_paths`, there is no value to the stubs.

The fourth module contains tests for creating environments with valid and
invalid names. Port these tests to module `test_environment_v2`.

Update the API documentation to reflect these changes.