upgrade to package-sets purescript v0.14.5

[waynevanson]

Description of the change

• Make compatible with latest package-sets (purescript-v0.14.5)
• Add CI strategy for better coverage

• Replace pulp and bower with spago (via spago init)

Checklist:

• [x] Added the change to the changelog's "Unreleased" section with a reference to this PR (e.g. "- Made a change (#0000)")
• [x] Linked any existing issues or proposals that this pull request should close
  • Closes #56
• [x] Updated or added relevant documentation
• [ ] Added a test for the contribution (if applicable)

[thomashoneyman]

I'm closing this for the reasons in #56, but thank you for the contribution and in the future we do want to do this!

[waynevanson]

That's okay, at least it will happen someday.