Add CI action workflows for testing and building

[simonhkswan]

Prior CI Workflow:

• Lint (custom flake8/mypy)
  • Test
    • Sonar Cloud

New CI Workflow:

• Lint (using pre-commit.ci which is free). This also autofixes whitespaces etc.
• Test (with coverage)
  • Sonar Cloud

[jamied157]

Looking good! Still not sure about this pre-commit stuff, if we're going to use mypy properly I think we have to use it explicitly

[simonhkswan]

Alright I think this should be pretty good now. I've found an even faster way and simpler way to run the pre-commit in CI and it's free so we're saving a few $ too 🎉

The End of line fixer and trailing whitespace marks also commits straight to the PR branch which is quite nice.

I've also updated the mypy config so that we are explicitly stating the packages which we are not type checking for clarity.

It looks like its now picking up the typing errors too (hopefully they're the ones you mentioned!)

@jamied157 let me know what you think!

[sonarqubecloud]

Kudos, SonarCloud Quality Gate passed!   

0 Bugs
0 Vulnerabilities
0 Security Hotspots
0 Code Smells

87.5% Coverage
0.0% Duplication