This ensures the InjectEnterpriseEditionModule cop is able to detect the
prepend patterns used in the qa/ directory. Previously it would not
detect them as all EE QA modules reside in QA::EE, and not the top-level
EE namespace.

Improve specs output readability by replacing
`it_behaves_like` with `include_examples`
in `BeSuccessMatcher`

Former shared examples were used only once.
Inlining them makes tests more clear.

Use Rubocop's Include
instead of manually checking the matcher in controllers specs.

BeSuccessMatcher now supports following examples:

```
expect(response).to be_success
expect(response).to_not be_success
expect(response).not_to be_success

is_expected.to be_success
is_expected.to_not be_success
is_expected.not_to be_success
```