bump node-apn to 5.1 to support 'interruption-level' and 'target-content-id'

Author: mman

package.json

@@ -33,7 +33,7 @@
     "nyc": "14.1.1"
   },
   "dependencies": {
-    "@parse/node-apn": "5.0.0",
+    "@parse/node-apn": "5.1.0",
     "@parse/node-gcm": "1.0.2",
     "npmlog": "4.1.2",
     "parse": "3.3.0"