Azuredns txt record too long , Skip alias entires

ZoneFileSource: allow users to specify file extension

Add fqdn module to setup.py as dependency

Forcing delete to happen before create

Fix indent of config/example.com.yaml in README.md

Co-authored-by: Ross McFarland <ross@github.com>

Refactor .git_hooks_pre-commit shell script syntax

Update development dependency - Twine to v3.2.0

Twine version < 2.0 was reported has a security vulnerability

From Twine version 2.0+, it requires Python 3.6, but doesn't seem to
have other breaking changes.

Reference:

- https://github.com/pypa/twine/issues/491
- https://twine.readthedocs.io/en/latest/changelog.html

manager: error when an alias zone is synced without its source

Signed-off-by: Marc 'risson' Schmitt <marc.schmitt@risson.space>

Updated document for unsafe thresholds

Ignore UltraDNS records with unsupported rrtypes and log warning.

Co-authored-by: Ross McFarland <ross@github.com>

Replace some nbsp chars that have slipped into manager.py somehow

Update links to octodns/octodns

fix: error in gandi.py

Also add Python v3.6, v3.8 on GitHub Actions for test

Unlike Python v2 as v2.7 is 10 years old, Python v3 has more versions
alive amoung us, it'll be great if they will all be tested.