This ensures that sphinx doc tests are ran and validated
and also runs doc8 to ensure style checks are done and adjusts
some of the current examples and code to fix found issues.
Also fixes the `get_callback_name` method which needs to check
if the __module__ is non-none (since it appears sphinx somehow
triggers it being none).
Change-Id: I54daecff219a9e9be71ff382d36fc2d5e67360cf
