chore(package): update fastify to version 0.15.0

https://greenkeeper.io/

Author: greenkeeper[bot]

package.json

@@ -25,7 +25,7 @@
   },
   "homepage": "https://github.com/fastify/fastify-redis#readme",
   "devDependencies": {
-    "fastify": "^0.14.0",
+    "fastify": "^0.15.0",
     "standard": "^10.0.0",
     "tap": "^10.3.1"
   },