fix(package): update keen-tracking to version 4.2.4

Closes #111

Author: greenkeeper[bot]

package.json

@@ -61,7 +61,7 @@
     "graphql-tag": "^2.8.0",
     "grid-styled": "^5.0.0",
     "isomorphic-fetch": "^2.2.1",
-    "keen-tracking": "^2.0.0",
+    "keen-tracking": "^4.2.4",
     "micro": "^9.1.4",
     "micro-route": "^2.4.0",
     "next": "^5.1.0",