Remove final from HttpAuthenticationFilter to allow overriding

Author: lauraluiz

common/app/com/commercetools/sunrise/httpauth/HttpAuthenticationFilter.java

@@ -22,7 +22,7 @@
 /**
  * Request filter that enables HTTP Access Authentication.
  */
-public final class HttpAuthenticationFilter extends Filter {
+public class HttpAuthenticationFilter extends Filter {
 
     private static final Logger LOGGER = LoggerFactory.getLogger(HttpAuthenticationFilter.class);