[0.2.2] Dependency changes and Makefile

This release sees mostly background improvements in the form of a Makefile, but it also has some dependency changes.

Added

• Added a Makefile to make testing the codebase easier/more streamlined locally on Linux/Unix platforms
• Added Tox as a development dependency

Changed

• Changed the README.md badge chain to a table with the badges split into categories
• Updated localisation files

Removed

• Removed pytest-runner as a development dependency, as it's useless with Poetry