fix(package): update form-data to version 2.1.4

https://greenkeeper.io/

Author: greenkeeper[bot]

package.json

@@ -5,7 +5,7 @@
   "main": "dist/workfront.js",
   "dependencies": {
     "es6-promise": "4.1.0",
-    "form-data": "2.1.2",
+    "form-data": "2.1.4",
     "isomorphic-fetch": "2.2.1",
     "workfront-api-constants": "2.0.0"
   },