Redis storage about botkit

[RafaelCosman]

So far people (including me) have been submitting PRs for these, but it's not clear if that's what the managers of the repo want. If they accept our PRs today then we'll know the answer.

[benbrown]

Yes! Please submit a pull request!! That is a great feature to have!

[guillaumepotier]

Okay @benbrown, I just submitted my PR in #38, feel free to comment. I factorized my code to handle the API that do not change much bw teams, users and channels and used a code that could be simpler with more lines. If not enough readable I could develop. What I particularly like with this implementation is that very easily you could add sets, I use that to store some of my application business (tokens or sessions to be able to call my API).

[RafaelCosman]

@guillaumepotier I left a note on your PR about passing storage_tests.js before we merge it.

[guillaumepotier]

Since my second pull request have been merged, I think we could close this issue.

Best