revert: node 16 upgrade is reverted (#132)

* revert: node 16 upgrade is reverted

* revert: reverted frontend build version to 9.1.2

* revert: browsers list

Co-authored-by: Awais Ansari <awais.ansari63@gmail.com>

.github/workflows/ci.yml

@@ -11,7 +11,7 @@ jobs:
     runs-on: ubuntu-latest
     strategy:
       matrix:
-        node: [16]
+        node: [12, 14, 16]
     steps:
     - name: Checkout
       uses: actions/checkout@v2