Django-mailprotector

- a major version is created when the software reached a milestone and is
feature complete

- add simple minifier to output. credits wullerot

- drop python2
- experimental django 4.0 support
- switch to github actions
- updated test matrix, django 2.2, 3.2, 4.0

- remove whitespace in links, so tel: links can be display like +41 22 575 333 333, but work anyway
- new release mode (no git-flow anymore), master is now main

- a minor version is created when a lot of new features have bene added or
significant backwards incompatible changes have been made.

- MAILPROTECTOR_EMAIL_LINK_PATTERN and MAILPROTECTOR_PHONE_LINK_PATTERN are no more used,
instead, a beautifulsoup based solution (more robust, can keep all attributes) is used.
- base for multiple protectors is made. for now, munger (as before) and munger_link_only are available
- django 3.0 is getting tested, removed django < 1.11 from tox