Update Node.js to v12.15.0 (#304)

Author: renovate-bot

package.json

@@ -82,7 +82,7 @@
     "verbose": true
   },
   "volta": {
-    "node": "12.14.1",
+    "node": "12.15.0",
     "yarn": "1.22.0"
   }
 }