Consolidate code of conduct

[bhrutledge]

It currently lives in this repo, and in https://github.com/BostonPython/code-of-conduct. Is this repo is its proper home? If so, should we close the other repo, and update external links as needed?

If we want to maintain it separately, but it could be a submodule of this repo?

[nedbat]

I think we should retire the other repo. It's a fork, but i don't think we were going to usefully get updates from the original.

[bhrutledge]

This link will need to be updated: http://bit.ly/bospy_cc

[nedbat]

There will be a bunch of links to update. Bitly doesn't let you change where a shortlink goes, so the best we can do for that is leave a message on the old page.