Internal:
- Modernize package repository [ericof] [71](https://github.com/collective/pas.plugins.authomatic/issues/71)
- Move tests to pytest [ericof] [72](https://github.com/collective/pas.plugins.authomatic/issues/72)
- Drop Plone 5.2 support [ericof] [80](https://github.com/collective/pas.plugins.authomatic/issues/80)
- Update i18n mechanism, update Brazilian Portuguese translation [ericof] [82](https://github.com/collective/pas.plugins.authomatic/issues/82)