fix(package): update slug to version 3.3.0

Closes #14

Author: greenkeeper[bot]

package.json

@@ -27,7 +27,7 @@
     "fastify-helmet": "^1.0.1",
     "moment": "^2.19.1",
     "rethinkdbdash": "^2.3.31",
-    "slug": "^0.9.1"
+    "slug": "^3.3.0"
   },
   "devDependencies": {
     "ava": "^0.23.0",