Monkey patch ddt.data when generating docs

Monkey patch ddt.data and robottelo's ddt.data wrapper, preventing the decorators from generating new test methods. Without this monkey patch, Sphinx might document the following methods:

* test_something_1_some_value
* test_something_2_another_value
* test_something_3_yet_another_value

But with this monkey patch, Sphinx will document only one test method:

* test_something

As a result, the API documentation is much more concise.

Thanks @Ichimonji10 for improving the comments with his nice suggestions.
s/generate/generating