Update changelog

Author: shalvah

CHANGELOG.md

@@ -15,7 +15,7 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 ## [3.7.1] - Thursday, 2 May 2019
 ### Fixed
-- Handle exception for no URL::forceRootURL() method in Lumen ()
+- Handle exception for no URL::forceRootURL() method in Lumen (https://github.com/mpociot/laravel-apidoc-generator/commit/2146fa114dc18bc32c00b5c5550266d753d5aef3)
 
 ## [3.7.0] - Thursday, 2 May 2019
 ### Added