Add GitHub Workflow to run tests

.github/workflows/test.yml

@@ -0,0 +1,22 @@
+name: Test
+
+on:
+  push:
+  pull_request:
+
+jobs:
+  test:
+    runs-on: ubuntu-latest
+    strategy:
+      matrix:
+        ruby-version: ['3.0']
+
+    steps:
+    - uses: actions/checkout@v3
+    - name: Set up Ruby
+      uses: ruby/setup-ruby@v1
+      with:
+        ruby-version: 3.0
+        bundler-cache: true
+    - name: Run tests
+      run: bundle exec rake