Add release steps

For my own edification. Relates to notes from #56 and #64.

Author: Kurt Yoder

RELEASE.md

@@ -0,0 +1,9 @@
+To release:
+* Verify pass in CircleCI
+* Update `CHANGELOG.md`
+* Update version in `setup.py`
+* `git push origin master`
+* Create/activate virtualenv: `pip install twine`
+* `python setup.py bdist_wheel --universal`
+* `twine upload dist/$(ls -tr dist/ | tail -1)`
+* Create Github release, named as version