Dont import module in setup anymore

[pltrdy]

• fixes missing dependency, six? #15.

[AlJohri]

@pltrdy here's one approach I use for the version btw: https://github.com/AlJohri/craigslist/blob/master/setup.py#L6

[AlJohri]

another more involved example: https://github.com/kennethreitz/setup.py/blob/master/setup.py#L40-L46

[pltrdy]

Thanks for pointing this out. I'm aware of those, but honestly, I think that it does not makes it super clear/simple. Duplicating isn't a good practice in general, but I think that it's really ok in this case.