github actions - add node.js 16

Author: liborm85

.github/workflows/lint-test.yml

@@ -13,7 +13,7 @@ jobs:
     strategy:
       fail-fast: false
       matrix:
-        node-version: [10.x, 12.x, 14.x]
+        node-version: [10.x, 12.x, 14.x, 16.x]
 
     steps:
     - uses: actions/checkout@v2