Fix props dict

Author: jeffcasavant

FuelSDK/rest.py

@@ -157,7 +157,7 @@ def __init__(self, auth_stub, obj_type, props = None, search_filter = None, opti
 
         if props is not None:
             if type(props) is dict: # If the properties is a hash, then we just want to use the keys
-                ws_retrieveRequest.Properties = props.keys
+                ws_retrieveRequest.Properties = props.keys()
             else:
                 ws_retrieveRequest.Properties = props