chore(deps): pin dependencies

Author: renovate-bot

package.json

@@ -22,8 +22,8 @@
     "workfront-api-constants": "2.0.0"
   },
   "devDependencies": {
-    "@types/form-data": "^2.2.1",
-    "@types/mocha": "^5.2.1",
+    "@types/form-data": "2.2.1",
+    "@types/mocha": "5.2.1",
     "codecov": "3.0.2",
     "dateformat": "3.0.3",
     "execa": "0.10.0",