fix(package): update @types/node to version 12.6.3

Closes #751

Author: greenkeeper[bot]

packages/admin-ui/package.json

@@ -21,7 +21,7 @@
     "@material-ui/core": "^3.2.0",
     "@material-ui/icons": "^3.0.1",
     "@types/jest": "^24.0.0",
-    "@types/node": "^11.13.3",
+    "@types/node": "^12.6.3",
     "@types/react": "^16.7.2",
     "@types/react-dom": "^16.0.9",
     "deepmerge": "^3.0.0",