Include Node.js 16 in the CI workflow

Author: axelrindle

.github/workflows/ci.yml

@@ -12,7 +12,7 @@ jobs:
     runs-on: ubuntu-latest
     strategy:
       matrix:
-        node-version: [10.x, 12.x, 14.x]
+        node-version: [10.x, 12.x, 14.x, 16.x]
 
     steps:
     - uses: actions/checkout@v2