chore(package): update supertest to version 3.4.2

Closes #129

Author: greenkeeper[bot]

package.json

@@ -27,7 +27,7 @@
     "mocha": "^4.0.0",
     "should": "^13.1.0",
     "semantic-release": "11.0.2",
-    "supertest": "3.0.0"
+    "supertest": "3.4.2"
   },
   "repository": {
     "type": "git",