Update for 1.6.1 release
Update release instructions to include `py37`,`py38`, and `doc` Tox envs
Update release instructions to mention testing via tox
Update for 1.5.2 release
Bump dev version
Update for 1.5.1 release
Update for 1.5.0 release
Update CHANGES.rst for 1.4.1 release
Add 3.6 classifier
Updated for 1.3.2 release