Add basic test workflow

.github/workflows/test.yml

@@ -0,0 +1,21 @@
+---
+name: test
+
+on:
+  push:
+    branches: [ main ]
+  pull_request:
+    branches: [ main ]
+
+jobs:
+
+  build:
+    runs-on: ubuntu-latest
+    steps:
+    - uses: actions/checkout@v2
+
+    - name: Install Go
+      uses: actions/setup-go@v2
+
+    - name: Build
+      run: make all