Problem with upgrading.

[shgninc]

Hi,
I try to upgrade the project by:

pip install --upgrade blo

but there as some problem:

Downloading/unpacking blo from https://pypi.python.org/packages/c8/d1/2604c0686f96f1d97e3b5ae6597282a11ace16cba344d1247e3f057d8c4f/blo-0.8.tar.gz#md5=7a7549a602c9b38cb985c386ac35761b
  Downloading blo-0.8.tar.gz
  Running setup.py (path:/tmp/pip_build_shgn/blo/setup.py) egg_info for package blo
    Traceback (most recent call last):
      File "<string>", line 17, in <module>
      File "/tmp/pip_build_shgn/blo/setup.py", line 5, in <module>
        with open(path.join(path.abspath(path.dirname(__file__)), 'README.rst'), encoding='utf-8') as f:
    TypeError: 'encoding' is an invalid keyword argument for this function
    Complete output from command python setup.py egg_info:
    Traceback (most recent call last):

  File "<string>", line 17, in <module>

  File "/tmp/pip_build_shgn/blo/setup.py", line 5, in <module>

    with open(path.join(path.abspath(path.dirname(__file__)), 'README.rst'), encoding='utf-8') as f:

TypeError: 'encoding' is an invalid keyword argument for this function
----------------------------------------
Cleaning up...
Command python setup.py egg_info failed with error code 1 in /tmp/pip_build_shgn/blo
Storing debug log for failure in /home/shgn/.pip/pip.log

How to solve it?