README.md in dor-workflow-client-3.20.1 vs README.md in dor-workflow-client-3.21.0

@@ -35,10 +35,10 @@
                      status: 'completed')
 ```
 
 Show "milestones" for an object
 ```ruby
-client.milestones('dor', 'druid:gv054hp4128')
+client.milestones(druid: 'druid:gv054hp4128')
 #=> [{version: '1', milestone: 'published'}]
 ```
 
 List workflow templates
 ```ruby