Removes extra getter method for getting returns member.

zipline/transforms/returns.py

@@ -37,7 +37,7 @@ class Returns(object):
         tracker = self.mapping[event.sid]
         tracker.update(event)
 
-        return tracker.get_returns()
+        return tracker.returns
 
     def _create(self):
         return ReturnsFromPriorClose(self.days)
@@ -56,9 +56,6 @@ class ReturnsFromPriorClose(object):
         self.returns = 0.0
         self.days = days
 
-    def get_returns(self):
-        return self.returns
-
     def update(self, event):
 
         if self.last_event: