the env.do(...) method produces both tuple and numpy.ndarray for the returned state.
Add print(type(obs)) after line 125 in evaluation.py to reproduce the following output:
Episode 6 (0.00)%
<type 'tuple'>
<type 'numpy.ndarray'>
<type 'tuple'>
<type 'numpy.ndarray'>
<type 'tuple'>
<type 'numpy.ndarray'>
<type 'tuple'>