Certbot-dns-desec

* f2fcc01: Increase TTL of TXT records to 3600

* 357ab00: Adds Badges to README
* 02c595d: Rewrite tests for Python 3.7
* 866c149: Moves default endpoint value to class variable
* ed74fbe: README: fixes ini file example

* 8ed04b7: Fix README code indentation
* 8f76127: Fix broken links in README
* 779496b: Also run tests for Python 3.9
* 6545d34: Convert README to markdown
* 25e67d1: Update README info

* 478d70d: Fixes README format

* e8533cb: Include maintainer info in README
* c2f8dcf: Adapt code base to deSEC API
* 82aa6ee: Renamed files and modules
* 5291388: Set update_serial to True
* 1f62744: Use specfic json exception
* 87c5f72: Remove unused variables or imports
* c037c28: dns_ispconfig.py: Fix default return values of _find_managed_zone_id
* 343f4e7: dns_ispconfig_test.py: Fix typo in function name in _register_response
* ff5aec2: Not mine (3)
* 9556ca6: Update README.rst
* 0d9f408: fixed author and formatting
* a2714b0: Do not update multiple challenges
* 9b9c6fb: fixed logging
* 534ea3a: fixed replacement of zone postfix
* cef0a0b: added logging and some improvements
* 45268e9: extended readme
* 0b76e29: Initial Version of plugin