Introduce with and without go modules testing

.github/workflows/go-mod.yml

@@ -0,0 +1,23 @@
+name: Go Modules
+
+on:
+  push:
+    branches: [ master ]
+  pull_request:
+    branches: [ master ]
+
+jobs:
+  build:
+    runs-on: ubuntu-latest
+    steps:
+    - uses: actions/checkout@v2
+    - name: Set up Go
+      uses: actions/setup-go@v2
+      with:
+        go-version: 1.18
+
+    - name: Test
+      run: |
+        cd v5
+        go get ./...
+        go test -v ./...

.github/workflows/go.yml

@@ -1,4 +1,4 @@
-name: Go
+name: Go (No Modules)
 
 on:
   push:
@@ -19,7 +19,7 @@ jobs:
     - name: Set up Go
       uses: actions/setup-go@v2
       with:
-        go-version: 1.18
+        go-version: 1.15
 
     - name: Test
       run: |