Drop dependency on sphinxcontrib-napoleon
Drop dependency on sphinxcontrib-napoleon

Since 1.3b1 (released Oct 10, 2014) Sphinx has support for NumPy and
Google style docstring support via sphinx.ext.napoleon extension.
The latter is already used, but sphinxcontrib-napoleon requirement
still presents.

Signed-off-by: Stanislav Levin <d8f28bdabcfedd2870feddb04c5f1bca6a417bec@altlinux.org>

mumrah/kafka-python,ohmu/kafka-python,scrapinghub/kafka-python,wikimedia/operations-debs-python-kafka,scrapinghub/kafka-python,ohmu/kafka-python,Aloomaio/kafka-python,DataDog/kafka-python,Aloomaio/kafka-python,dpkp/kafka-python,wikimedia/operations-debs-python-kafka,mumrah/kafka-python,Yelp/kafka-python,Yelp/kafka-python,dpkp/kafka-python