Update default runtime to node16 (#192)

.github/workflows/workflow.yml

@@ -19,10 +19,10 @@ jobs:
       - name: Checkout
         uses: actions/checkout@v2
 
-      - name: Setup node 12
+      - name: Setup node 16
         uses: actions/setup-node@v2
         with:
-          node-version: 12
+          node-version: 16
           cache: npm
 
       - name: npm ci