feat(ci) use Node 16 / npm 8 for testing

.github/workflows/ci.yml

@@ -10,8 +10,7 @@ jobs:
     - uses: actions/checkout@v2
     - uses: actions/setup-node@v1
       with:
-        node-version: '14.x'
-    - run: npm i -g npm@7
+        node-version: '16.x'
     - run: npm install
     - name: Check git status
       run: git status