build: CI: switch to Node.js 14 (#254)

Co-authored-by: Justin Beckwith <beckwith@google.com>

Author: XhmikosR

.github/workflows/ci.yaml

@@ -5,7 +5,7 @@ on:
   pull_request:
 name: ci
 env:
-  NODE: 12
+  NODE: 14
 jobs:
   test:
     runs-on: ubuntu-latest