misc(ci): Add GitHub Action

Commands and versions from previous, removed .travis.yml configuration.

.github/workflows/go.yml

@@ -0,0 +1,20 @@
+# This workflow will build a golang project. For more information see: https://docs.github.com/en/actions/automating-builds-and-tests/building-and-testing-go
+name: Go
+on: [push, pull_request]
+jobs:
+  build:
+    runs-on: ubuntu-latest
+    strategy:
+      matrix:
+        go: [ '1.9', '1.10.x', '1.14.x' ]
+    name: Go ${{ matrix.go }}
+    steps:
+    - uses: actions/checkout@v4
+    - name: Set up Go ${{ matrix.go }}
+      uses: actions/setup-go@v5
+      with:
+        go-version: ${{ matrix.go }}
+    - name: Build
+      run: go build mumble.info/grumble/cmd/grumble
+    - name: Test
+      run: go test -v ./...