Use Node 12 in gradle.yml

Author: netzartist

.github/workflows/gradle.yml

@@ -11,7 +11,7 @@ jobs:
     - uses: actions/checkout@v1
     - uses: actions/setup-node@v1
       with:
-        node-version: '10.x'
+        node-version: '12.x'
     - name: Install NPM
       run: cd client && npm install
     - name: Build provisioning-app FE