ci: add test task on github

.github/workflows/main.yml

@@ -0,0 +1,38 @@
+# This CI job installs Crystal and shard dependencies, then executes `crystal spec` to run the test suite
+# More configuration options are available at https://crystal-lang.github.io/install-crystal/configurator.html
+
+name: Exec Lib
+
+on:
+  workflow_dispatch:
+  pull_request:
+  push:
+    branches:
+      - master
+      - dev
+
+concurrency: 
+  group: ${{ github.sha }}
+  cancel-in-progress: true
+
+jobs:
+  test:
+    strategy:
+      matrix:
+        crystal: 
+        - "1.0.0"
+        - latest
+    runs-on: ubuntu-latest
+    steps:
+      - name: Download source
+        uses: actions/checkout@v4
+      - name: Install Crystal
+        uses: crystal-lang/install-crystal@v1
+        with:
+          crystal: ${{ matrix.crystal }}
+      - name: Install shards
+        run: shards update --ignore-crystal-version
+      - name: Check formatting
+        run: crystal tool format --check
+      - name: Run tests
+        run: crystal spec --order=random