Add actions

.github/workflows/build.yml

@@ -0,0 +1,18 @@
+on: [push, pull_request]
+name: Build
+jobs:
+  test:
+    strategy:
+      matrix:
+        go-version: [1.16.x, 1.17.x]
+        os: [ubuntu-latest, macos-latest, windows-latest]
+    runs-on: ${{ matrix.os }}
+    steps:
+    - name: Install Go
+      uses: actions/setup-go@v2
+      with:
+        go-version: ${{ matrix.go-version }}
+    - name: Checkout code
+      uses: actions/checkout@v2
+    - name: Build
+      run: go build ./...