Implement full matrix test builds (Travis / Github Actions)

Created by: fsoubelet

It is time to test our package(s) on all supported python versions across major operating systems.

From personal experience:

• Travis builds are extremely slow under a big matrix as only 2 or 3 will run concurrently
• Travis' macOS VMs take a very long time to spin up (~10-15 min)
• Travis support for Windows is still experimental.
• Github Actions don't have these problems
• Github Actions "only" offers macos-latest and windows-latest for these systems.

I started setting up github actions in the feature/github_actions branch. This was branched off from bugs/219/madx_macros as it should soon be merged into master, but did reset the tfs-pandas dependency to >=1.0 in order for the install step to not fail

We're expecting to find bugs in the new builds, will gather findings in this issue.

Commits that were pushed previously without referencing this issue: 92bed47, 73a3cf3, 6474dba and 10cf7b0