fix(package): update nodemailer to version 6.1.0

Author: greenkeeper[bot]

package.json

@@ -72,7 +72,7 @@
     "method-override": "~3.0.0",
     "mongoose": "~5.4.19",
     "multer": "~1.4.1",
-    "nodemailer": "~6.0.0",
+    "nodemailer": "~6.1.0",
     "nodemon": "^1.18.10",
     "object-path": "^0.11.4",
     "passport": "^0.4.0",