Add CI and add explicit dependency versioning to all workflows #6

	name: Crystal CI
	on:
	pull_request:
	branches: [ "main" ]
	jobs:
	build:
	runs-on: ubuntu-latest
	steps:
	- uses: actions/setup-node@v4
	with:
	node-version: 20.x
	- uses: crystal-lang/install-crystal@v1
	with:
	crystal: 1.6.2
	- name: Download source
	uses: actions/checkout@v4
	- name: Install dependencies
	run: shards install
	- name: Run tests
	run: crystal spec

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