Release v0.19.0

[andymeneely]

Be sure to remember to do the following for releases.

• [x] CHANGELOG is written for all new changes
• [x] README is updated
• [x] Samples are updated
• [x] Are all the dependencies up to date?
• [x] Check sample_regression_spec.rb regression tests are all enabled (i.e. overwrite_sample is commented out)
• [x] Bump version.rb
• [x] Bump docs/conf.py versions
• [x] Do a full rake locally
• [x] rake sanity, and check visually
• [ ] GitHub Actions is passing on dev branch
• [ ] Merge master branch
• [x] Merge release branch
• [x] Push master and release branches
• [x] Create GitHub release tag
• [x] gem push pkg/squib-x.y.z.gem
• [x] Github milestone closed
• [x] Activate version on squib.readthedocs.org (Versions)
• [x] Set default version on squib.readthedocs.org (Advanced Settings)
• [x] Bump version.rb to the next alpha
• [x] Publish on BoardGameGeek thread

• [x] Anything else to add to this checklist?

  Docker

• [x] Check Dockerfile for updates
• [x] docker build .
• [ ] docker tag XYZ andymeneely/squib:latest
• [ ] docker tag XYZ andymeneely/squib:version-0.XYZ.0
• [ ] docker push andymeneely/squib:latest
• [ ] docker push andymeneely/squib:version-0.XYZ.0
• [ ] Check Docker build on Dockerhub: https://hub.docker.com/repository/docker/andymeneely/squib
• [ ] Check Docker docker pull: docker pull andymeneely/squib:latest
• [ ] Check Docker build locally in samples:
  • Delete samples/_output/basic_*.png
  • docker run --rm -v c:\code\squib\samples:/usr/src/app -w /usr/src/app andymeneely/squib:latest ruby basic.rb
  • Check that the files were made
• [ ] Anything else to add to this checklist?