github: add a CI workflow

.github/workflows/ci.yml

@@ -0,0 +1,27 @@
+name: Go
+
+on:
+  push:
+    branches:
+      - master
+  pull_request:
+    branches:
+      - master
+
+jobs:
+
+  build:
+    runs-on: ubuntu-latest
+    steps:
+    - uses: actions/checkout@v2
+
+    - name: Set up Go
+      uses: actions/setup-go@v3
+      with:
+        go-version: 1.16
+
+    - name: Build
+      run: go build -v ./...
+
+    - name: Test
+      run: go test -v ./tests