Please create or document your change log

[mlissner]

I've looked in the following places:

1. Readme in github
2. Changelog.rst in github
3. Github releases feature
4. The Github pages site
5. The docs directory

And I haven't been able to find anything explaining what changes this package may have.

Am I missing something? If not, would it be possible to start keeping this log so folks can be sure that upgrades will go smoothly?