Add PatchWise tests to GitHub Actions

[davidgantman]

Is your feature request related to a problem? Please describe.
PatchWise isn't being regression tested currently.

Describe the solution you'd like
Run patchwise --help after every change, successfully.

[ethanreidel]

Can work on this.

[davidgantman]

Can work on this.

@ethanreidel, I'll assign this to you if no one else volunteers, or once you close #26