Pinax-blog

* [Release Notes](https://github.com/pinax/pinax-blog801)

* [Release Notes](https://github.com/pinax/pinax-blog800)

* Fix migration missing on_delete=

* Restore and improve documentation guidance for pinax-images usage

* Replace pinax-theme-bootstrap test dependency with pinax-templates
* Update pinax-images requirement

* Add Django 2.0 compatibility testing
* Drop Django 1.8, 1.9, 1.10 and Python 3.3 support
* Move documentation into README, and standardize layout
* Convert CI and coverage to CircleCi and CodeCov
* Add PyPi-compatible long description
* Bump minimum required version of pinax-images to v3.0.0 for Django 2.0 compatibility