fixing sendgrid lib version to 6.3.0

Author: Sachin Maheshwari

package.json

@@ -19,8 +19,8 @@
     "mocha": "^5.0.0"
   },
   "dependencies": {
-    "@sendgrid/client": "6.3.1",
-    "@sendgrid/mail": "6.3.1",
+    "@sendgrid/client": "6.3.0",
+    "@sendgrid/mail": "6.3.0",
     "bluebird": "^3.5.1",
     "body-parser": "^1.15.2",
     "co": "^4.6.0",