Test on GH actions.

Author: rkistner

.github/workflows/test.yaml

@@ -0,0 +1,18 @@
+name: Test
+
+on:
+  push:
+    branches:
+      - "**"
+
+jobs:
+  build:
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v3
+      - uses: dart-lang/setup-dart@v1
+
+      - run: dart pub get
+      - run: dart format --output=none --set-exit-if-changed .
+      - run: dart analyze
+      - run: dart test