setup py uplift requirements

[torbjorgen]

• setup.py: Uplift install_requires to fit to requirements.py
• Makefile: Add target for testing distribution
• Makefile: pytest, view passed tests
• Run tests in github actions

[jemten]

Should we bump the python version to a minimum of 3.8 to reflect that 3.7 has reached its end of life?

[torbjorgen]

• Bumped python version to v3.8 according to @jemten suggestion.