chore(package): update supertest to version 4.0.1

Closes #43

Author: greenkeeper[bot]

package.json

@@ -46,7 +46,7 @@
 		"lint-staged": "^7.0.4",
 		"mocha": "^5.1.1",
 		"strip-ansi": "^4.0.0",
-		"supertest": "^3.0.0"
+		"supertest": "^4.0.1"
 	},
 	"dependencies": {
 		"chalk": "^2.4.0",