Write support

[jayvdb]

I dont see write support

Also it appears that mode w is not recognised - it should cause a NotImplementedError at the moment until write support is implemented.

https://pypi.org/project/xopen/ has pretty good write support.

[jayvdb]

My motivation for wanting it was to build test cases for jerith/landinggear#3

But the same would be quite beneficial for dephell tests in general ; instead of storing specific archives in the repos for testing, those scenarios could be easily built by creating archives which exhibit the various curious cases needing tests.

Note that I didnt find any part of wheel which allowed easy creation of a WHEEL file outside of setuptools, so I needed to create my own fake logic in above PR which could be the basis for a real generator.