.github: add testing workflow

.github/workflows/go.yml

@@ -0,0 +1,20 @@
+name: Go
+
+on:
+  pull_request:
+    branches: [ master ]
+
+jobs:
+
+  tests:
+    runs-on: ubuntu-latest
+    steps:
+    - uses: actions/checkout@v2
+
+    - name: Set up Go
+      uses: actions/setup-go@v2
+      with:
+        go-version: 1.17
+
+    - name: Test
+      run: go test -v ./...