fix(package): update level to version 6.0.1

Closes #14

Author: greenkeeper[bot]

package.json

@@ -35,7 +35,7 @@
     "debug": "^3.1.0",
     "joi": "^13.1.2",
     "length-prefixed-message": "^3.0.3",
-    "level": "^3.0.0",
+    "level": "^6.0.1",
     "network-address": "^1.1.2",
     "request-ip": "^2.0.2",
     "scuttleup": "^3.3.0"