Update go version, modules and remove ioutil

.github/workflows/ci.yaml

@@ -65,11 +65,11 @@ jobs:
       - name: Checkout
         uses: actions/checkout@v2
 
-      - name: Set up Go 1.15
+      - name: Set up Go 1.16
         id: go
         uses: actions/setup-go@v2
         with:
-          go-version: 1.15
+          go-version: 1.16
 
       - name: Set up Docker Buildx
         id: buildx