fix typo

api_interfaces.go

@@ -49,7 +49,7 @@ type FindAll interface {
 }
 
 // The InitializeObject interface can be implemented to have the ability to change
-// a created object before Unmarshal is called. This is currently on called on
+// a created object before Unmarshal is called. This is currently only called on
 // Create as the other actions go through FindOne or FindAll which are already
 // controlled by the implementer.
 type InitializeObject interface {