* Python client pure library package
* check onlyPackage CLI option
* run /bin/python-petstore.sh, update the python samples for CI
* onlyPackage local variable instead of classp property
* fix CI: __future__ absolute_import must be first in file
* update samples
* generateSourceCodeOnly
* updated samples
`unicode` does not exist in py3, therefore since six is already imported
switch to using `six.u` so that `unicode` is used on py2 and `str` is used
on py3.
The linting results for the generated samples are as follows
where the first number is the BEFORE and the second is AFTER.
pyclient 7714 vs. 120
pyclient3 7717 vs. 120
pyclient3-asyncio 7584 vs. 120
pyclient-tornado 7633 vs. 120
pyclient3-tornado 7633 vs. 120
For the complete details please see the following gist.
https://gist.github.com/kenjones-cisco/2eb69a7e8db75e9fd53789f01570d9f2
Enforces linting for python clients by running flake8 for the generated
python client.
