fixing sendgrid/helpers lib to 6.3.0

Author: Sachin Maheshwari

package.json

@@ -20,7 +20,8 @@
   },
   "dependencies": {
     "@sendgrid/client": "6.3.0",
-    "@sendgrid/mail": "6.3.0",
+    "@sendgrid/mail": "6.3.1",
+    "@sendgrid/helpers": "6.3.0",
     "bluebird": "^3.5.1",
     "body-parser": "^1.15.2",
     "co": "^4.6.0",