Merge pull request #3008 in SW/shopware from add-behat-version-pop-to-upgrade-md to 5.1

* commit '09a08256a3ac442456f1370005375ff898135649':
  Add Behat version upgrade to UPGRADE.MD

Author: bcremer

UPGRADE.md

@@ -3,6 +3,7 @@ In this document you will find a changelog of the important changes related to t
 
 ## 5.1.0
 * Added event `Shopware_Plugin_Collect_MediaXTypes` to collect media related x_type fields for which the value needs to be normalized
+* Updated Behat to v3.0 and other related libraries
 
 ## 5.1.0 RC3
 * Activated media fallback by default so that old media paths get resolved to the new location