Upgrade node version in CI to v12.x

Author: webholik

.github/workflows/integration.yml

@@ -11,7 +11,7 @@ jobs:
       - name: Setup Node JS
         uses: actions/setup-node@v1
         with:
-          node-version: '8.x'
+          node-version: '12.x'
       - name: Install system dependencies
         run: npm run cirequirements
       - name: Install package dependencies

package.json

@@ -54,6 +54,6 @@
     "watchify": "3.11.1"
   },
   "engines": {
-    "node": ">=6"
+    "node": ">=12"
   }
 }