fix(package): update ioredis to version 4.0.0 (#285)

Author: greenkeeper[bot]

package.json

@@ -19,7 +19,7 @@
     "bcryptjs": "^2.4.3",
     "debug": "^3.1.0",
     "escape-string-regexp": "^1.0.5",
-    "ioredis": "^3.2.2",
+    "ioredis": "^4.0.0",
     "lodash": "^4.16.3",
     "mongoose": "^5.2.0",
     "ms": "^2.1.1",