Add some recent releases to README.md

README.md

@@ -4,7 +4,7 @@ Ansible Tower
 Tower provides a web-based user interface, REST API and task engine built on top of
 Ansible.
 
-The current version under development is 2.1.0.
+The current version under development is 2.2.1.
 
 Development releases always use the 'master' branch.
 
@@ -31,6 +31,9 @@ Release History
 * 2.1.2, March 25, 2015
 * 2.1.3, April 15, 2015
 * 2.1.4, June 12, 2015
+* 2.1.5, June 15, 2015
+* 2.1.6, June 23, 2015
+* 2.2.0, July 14, 2015
 
 Any fixes should be applied on the appropriate release branch and be cherry-picked to
 master.