Setup CI, tox/tests, pyInstaller on relevant platforms

[ryanwersal]

No description provided.

[ryanwersal]

Looking at TravisCI, Appveyor, and Azure DevOps (specifically Azure Pipelines) it appears that Azure Pipelines is the likely winner since it supports all three platforms.

[zvekovius]

Made a Azure for Devops org "Sabergen". Hit me up with your azure deets and I'll add you as an admin.
@ryanwersal noted it looked like it was under my name. Figured out how to get it to appear as a proper org and ryan is also an admin in azure devops meow.

[ryanwersal]

I got a super basic Pipelines config rolling. It is interesting though that pipenv isn't actually intended for isolating many versions of Python. Their docs indicate that they are "deployment tool" and, as such, should only target all Python versions or a single required version.

Though they do say "ideally" so it may be possible. I disabled the matrix of versions for the time being.

[ryanwersal]

Ended up using a matrix build on GH Actions. Need to figure out sndfile stuff for macOS and Windows but at the very least we won't need to worry about tox and co for now.