[action] use go version matrix for the test / build step

.github/workflows/test.yml

@@ -11,7 +11,10 @@ on:
 jobs:
   lintTestBuild:
     name: Lint, Test, Build
-    runs-on: ubuntu-latest
+    runs-on: ubuntu-20.04
+    strategy:
+      matrix:
+        go: [ '1.15', '1.16' ]
     steps:
       -
         name: Checkout
@@ -20,7 +23,7 @@ jobs:
         name: Setup Go
         uses: actions/setup-go@v2
         with:
-          go-version: '1.15.6'
+          go-version: ${{ matrix.go }}
       -
         name: Install Deps
         id: install-deps