passing some tests on py3, all on py2

rowers/utils.py

@@ -206,7 +206,7 @@ def uniqify(seq, idfun=None):
 
 def serialize_list(value,token=','):
     assert(isinstance(value, list) or isinstance(value, tuple) or isinstance(value,np.ndarray))
-    return token.join([s for s in value])
+    return token.join([str(s) for s in value])
 
 def deserialize_list(value,token=','):
     if isinstance(value, list):