chore(release): version 3.1.3 [skip ci]

<a name="3.1.3"></a>
## [3.1.3](v3.1.2...v3.1.3) (2018-02-09)

### Bug Fixes

* randomize socket suffix ([#120](#120)) ([f747eca](f747eca))

package.json

@@ -1,6 +1,6 @@
 {
   "name": "aws-serverless-express",
-  "version": "3.1.2",
+  "version": "3.1.3",
   "description": "This library enables you to utilize AWS Lambda and Amazon API Gateway to respond to web and API requests using your existing Node.js application framework.",
   "keywords": [
     "aws",