Update node-notifier (has mem leak fix)

Summary:
Noticed that we're on a version of node-notifier that has a leak mentioned [here](mikaelbr/node-notifier#183) and fixed in the newest version.

Automated tests

 [INTERNAL] [BUGFIX] [package.json] - Update node-notifier dependency
Closes #18033

Differential Revision: D7102637

Pulled By: hramos

fbshipit-source-id: 850f3d826c1d880a6281d95e4d5af68e9af89927

package.json

@@ -181,7 +181,7 @@
     "mkdirp": "^0.5.1",
     "morgan": "^1.9.0",
     "node-fetch": "^1.3.3",
-    "node-notifier": "^5.1.2",
+    "node-notifier": "^5.2.1",
     "npmlog": "^2.0.4",
     "opn": "^3.0.2",
     "optimist": "^0.6.1",