* fixing "decoding Unicode is not supported" error for py2 when data is unicode
* allowing nonstandard methods for tornado python client.
* Making sure to return unicode when needed
`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.
