The `test_quota` and `test_policy` modules
don't need to be documented, since they present
no meaningful information to contributors.
Removing these also avoids the docstring
formatting issues that ddt may introduce
to the sphinx build. [1]
[1] https://github.com/datadriventests/ddt/pull/51
Change-Id: I8136e8a000e04bcc213a746c7d793bf9373b1b38
Closes-Bug: #1783124
2b389ce1e1