Update README.md (#7615)

Added Husbanken who uses swagger-codegen to specify, document and generate api-stubs for internal web-services.

Author: jarlesat

README.md

@@ -799,6 +799,7 @@ Here are some companies/projects using Swagger Codegen in production. To add you
 - [High Technologies Center](http://htc-cs.com)
 - [Hootsuite](https://hootsuite.com/)
 - [Huawei Cloud](http://www.huaweicloud.com/en-us/product/cs.html) 
+- [Husbanken](https://www.husbanken.no)
 - [IBM](https://www.ibm.com)
 - [IMS Health](http://www.imshealth.com/en/solution-areas/technology-and-applications)
 - [Individual Standard IVS](http://www.individual-standard.com)