REL: Release 0.2.1

[davidastephens]

Will do a release this week to get the ability to use request sessions on the pypi version.

Anyone feel like writing some docs for it?

@femtotrader ?

[femtotrader]

I don't feel really confortable at writing doc as my mother tongue is not english.

Moreover I think we need to rewrite wb.py before releasing (because it's better to support caching with all data reader)

[davidastephens]

I think @sinhrks took care of that in #121.

Feel free to take a stab at it and I can edit it if you have time. I've never used requests sessions or the requests cache.

[femtotrader]

Yes you are right but we should also have session passed to others functions in wb.py

[femtotrader]

This PR is a first try for a doc #126

[davidastephens]

All good for a release tomorrow?

[femtotrader]

I think that's ok.