add github action to build

.github/workflows/build.yml

@@ -0,0 +1,27 @@
+name: build
+
+on: [push, pull_request]
+
+jobs:
+  build:
+    name: Build
+    runs-on: ${{ matrix.os }}
+    strategy:
+      matrix:
+        os: [ubuntu-latest, windows-latest, macos-latest]
+        go-version: [1.12]
+
+    steps:
+    - name: Set up Go ${{ matrix.go-version }}
+      uses: actions/setup-go@v2
+      with:
+        go-version: ${{ matrix.go-version }}
+
+    - name: Check out code into the Go module directory
+      uses: actions/checkout@v2
+
+    - name: Get dependencies
+      run: go get -v -t -d ./...
+
+    - name: Build
+      run: go build -v ./