fix(package): update express to version 4.17.1

Closes #79

Author: greenkeeper[bot]

package.json

@@ -60,7 +60,7 @@
     "esdb-categorize": "0.0.5",
     "eth-phishing-detect": "1.1.13",
     "ethereum-ens": "0.7.4",
-    "express": "4.16.4",
+    "express": "4.17.1",
     "flat": "4.1.0",
     "fs-extra": "7.0.1",
     "github-api": "3.0.0",