Collectd-transmission

After almost 5 years, let's release a new version, 3.3

This release is mostly about bringing the software up to date with
current python practices

Detailed changelog is below

* e82c0f0 - Remove travis badge from README.rst - Alexandros Kosiaris
* 141951c - Remove requirements.txt - Alexandros Kosiaris
* 90cebc0 - Remove .travis.yml - Alexandros Kosiaris
* 93699e5 - Switch to pyproject.toml - Alexandros Kosiaris
* 7fd1a08 - Switch from distutils.version to packaging.version - Alexandros Kosiaris
* ce76b79 - GH actions: Add python 3.11 - Alexandros Kosiaris
* 6cabac6 - Add a docstring to setup.py - Alexandros Kosiaris
* 829effb - Ignore a wrong-import-position pylint warning - Alexandros Kosiaris
* 24303f6 - pylint: Ignore a few import errors - Alexandros Kosiaris
* 537176e - Rename a test function to appease pylint - Alexandros Kosiaris
* 566e1d9 - Use an f-string instead of %- formatting - Alexandros Kosiaris
* 22309b6 - Switch to unittest.mock - Alexandros Kosiaris
* 1b6336c - Satisfy a flake8 warning - Alexandros Kosiaris
* 66c768e - Add pytest to tox - Alexandros Kosiaris
* 95ce102 - Add python package GH action - Alexandros Kosiaris
* cc176e5 - Install of test-requirements in pylint - Alexandros Kosiaris
* c87b03d - Add pylint in tox - Alexandros Kosiaris
* caa71d8 - Update tox configuration - Alexandros Kosiaris
* 571c6c8 - Make pylint a bit happier - Alexandros Kosiaris
* 61b73fc - Create pylint.yml - Alexandros Kosiaris

Minor update. No functional changes but:

* Dropped support for python 3.3
* Added support for python 3.6
* Dropped support for transmissionrpc < 0.9

This is the first release to also provide a universal wheel. It also incorporates changes to gracefully recover from any loss of connection to a running transmission server due to restarts, network issues etc. It effectively fixes an issue where collectd had to be restarted after any of the above events caused the connection to the transmission server to break.

This release is practically the same as 2.3, but it had it's version number bumped to 3.0 to reflect the fact the project is migrating to Semantic Versioning

Major highlights:
- 100% code coverage
- supporting officially python 3.3, python 3.4
- readthedocs.org integration

- Fix bug 1
- Other minor issues