update build to run on newer versions of go

.github/workflows/go.yml

@@ -5,18 +5,21 @@ on:
     branches: [ master ]
   pull_request:
     branches: [ master ]
+  workflow_dispatch:
 
 jobs:
 
   build:
     name: Build
     runs-on: ubuntu-latest
+    strategy:
+      matrix:
+        go: [ '^1.14', 'oldstable', 'stable' ]
     steps:
-
     - name: Set up Go 1.x
-      uses: actions/setup-go@v2
+      uses: actions/setup-go@v3
       with:
-        go-version: ^1.14
+        go-version: ${{ matrix.go }}
       id: go
 
     - name: Check out code into the Go module directory