Move to GitHub Actions

[robertodr]

Let's fix CI, which is currently rotten and useless for incoming PRs.

Description

• Use Poetry to manage Python requirements
• Move to GitHub actions for testing
  • Linux with GNU toolchain
  • Linux with Intel toolchain
  • Linux with PGI toolchain
  • macOS
  • Windows

Types of changes

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to change)

Status

• Ready to go

[bast]

Thanks for starting this. I will soon help out here. I agree that we need to restore testing otherwise it's like flying through the fog without instruments.

[robertodr]

Not much luck, currently, but that's because testing has many layers for this project.

First strep is to green up Linux/macOS and phase out Travis. Then phase out CircleCI (which is running custom PGI and Intel images, both rotten...) Phase out of AppVeyor comes last and I believe that will be the greatest amount of work...

What I would like to achieve:

1. Unpack testing of each chapter in its own sub-action. It's easier to see what's failing and each chapter gets a badge.
2. Redo Docker images for use with Actions, so that we can also "unpack" successes/failures by Docker image.