Added build badge

Author: dilipkrish

README.md

@@ -1,6 +1,6 @@
 # springfox-javadoc
 
-[![Codacy Badge](https://api.codacy.com/project/badge/Grade/32f99b3650794b5eb1f7c155a57d5100)](https://app.codacy.com/app/dilip-krishnan-github/springfox-javadoc?utm_source=github.com&utm_medium=referral&utm_content=springfox/springfox-javadoc&utm_campaign=badger)
+[![CircleCI](https://circleci.com/gh/springfox/springfox-javadoc.svg?style=svg)](https://circleci.com/gh/springfox/springfox-javadoc) [![Codacy Badge](https://api.codacy.com/project/badge/Grade/32f99b3650794b5eb1f7c155a57d5100)](https://app.codacy.com/app/dilip-krishnan-github/springfox-javadoc?utm_source=github.com&utm_medium=referral&utm_content=springfox/springfox-javadoc&utm_campaign=badger)
 
 Ability to use Javadoc for documentation for generating OpenAPI specifications