Docs and published version mismatch

[ilouzl]

Currently the docs is up to date with master, which might be ahead of the pipy release.
The docs should have a version picker (using mike?) and a release note page as well (derived from HISTORY.md).
The docs may only be deployed on new pypi publishes.

[ilouzl]

Also an auto updater of HISTORY.md is needed - on every new pypi deployment - based on the PR merges into master

[ilouzl]

closed with #48