On Debian Jessie with pip install :

Complete output from command python setup.py egg_info:
    Traceback (most recent call last):
      File "<string>", line 20, in <module>
      File "/tmp/pip-o_ERWm-build/setup.py", line 16, in <module>
        with open('requirements.txt', encoding='utf-8') as reqs:
    TypeError: 'encoding' is an invalid keyword argument for this function