add env and fix url for golang.org

.github/workflows/go-workflow-1.yml

@@ -1,4 +1,4 @@
-name: v2 Test @ Go 1.11
+name: Build and Test
 
 on:
   pull_request:
@@ -6,16 +6,82 @@ on:
       master
 
 jobs:
-  test:
-    name: Build & Test
+  test1:
+    name: Test @ Go 1.11
     runs-on: ubuntu-latest
+    env:
+      GO111MODULE: on
+      GOPROXY: https://proxy.golang.org
     steps:
+      - name: Set up Go 1.11
+        uses: actions/setup-go@v1
+        with:
+          go-version: 1.11
+
+      - name: Checkout Code
+        uses: actions/checkout@v1
+
       - name: Install Dependencies
         run: |
           go get github.com/urfave/gfmrun/cmd/gfmrun
-          go get golang/x/tools/cmd/goimports
+          go get golang.org/x/tools/cmd/goimports
+          npm install markdown-toc
+
+      - name: Run Tests
+        run: |
+          go run build.go vet
+          go run build.go test
+          go run build.go gfmrun docs/v2/manual.md
+          go run build.go toc docs/v2/manual.md
+  test2:
+    name: Test @ Go 1.12
+    runs-on: ubuntu-latest
+    env:
+      GO111MODULE: on
+      GOPROXY: https://proxy.golang.org
+    steps:
+      - name: Set up Go 1.12
+        uses: actions/setup-go@v1
+        with:
+          go-version: 1.12
+
+      - name: Checkout Code
+        uses: actions/checkout@v1
+
+      - name: Install Dependencies
+        run: |
+          go get github.com/urfave/gfmrun/cmd/gfmrun
+          go get golang.org/x/tools/cmd/goimports
+          npm install markdown-toc
+
+      - name: Run Tests
+        run: |
+          go run build.go vet
+          go run build.go test
+          go run build.go gfmrun docs/v2/manual.md
+          go run build.go toc docs/v2/manual.md
+  test3:
+    name: Test @ Go 1.13
+    runs-on: ubuntu-latest
+    env:
+      GO111MODULE: on
+      GOPROXY: https://proxy.golang.org
+    steps:
+      - name: Set up Go 1.13
+        uses: actions/setup-go@v1
+        with:
+          go-version: 1.13
+
+      - name: Checkout Code
+        uses: actions/checkout@v1
+        with:
+          ref: $GITHUB_REF
+
+      - name: Install Dependencies
+        run: |
+          go get github.com/urfave/gfmrun/cmd/gfmrun
+          go get golang.org/x/tools/cmd/goimports
           npm install markdown-toc
-          go mod tidy
 
       - name: Run Tests
         run: |