Update moment to resolve ReDOS attack.

Author: TimFerrell

package.json

@@ -15,7 +15,7 @@
   "license": "MIT",
   "dependencies": {
     "async": "~0.2.9",
-    "moment": "2.15.2",
+    "moment": "2.19.3",
     "valid-url": "~1.0.9",
     "xml-crypto": "~1.0.1",
     "xml-encryption": "0.11.2",