fix(package): update bottleneck to version 2.18.0

Closes #78

Author: greenkeeper[bot]

package.json

@@ -23,7 +23,7 @@
   },
   "dependencies": {
     "aws-sdk": "^2.293.0",
-    "bottleneck": "^1.16.0",
+    "bottleneck": "^2.18.0",
     "debug": "^3.1.0",
     "lodash.isempty": "^4.2.1",
     "winston-transport": "^4.2.0"