title: Failing installation of tensorpack
body: <p>I'm trying to install tensorpack on Ubuntu 16.04 LTS.</p>
  
  <pre><code>$ sudo -H pip install --upgrade tensorpack
  Collecting tensorpack
    Using cached tensorpack-0.1.7-py2.py3-none-any.whl
  Collecting tabulate (from tensorpack)
    Using cached tabulate-0.7.7-py2.py3-none-any.whl
  Collecting termcolor (from tensorpack)
    Downloading termcolor-1.1.0.tar.gz
  Requirement already up-to-date: six in /usr/lib/python3/dist-packages (from tensorpack)
  Requirement already up-to-date: numpy in /usr/local/lib/python3.5/dist-packages (from tensorpack)
  Collecting subprocess32 (from tensorpack)
    Using cached subprocess32-3.2.7.tar.gz
      Complete output from command python setup.py egg_info:
      This backport is for Python 2.x only.
  
      ----------------------------------------
  Command "python setup.py egg_info" failed with error code 1 in /tmp/pip-build-3vdwf8jw/subprocess32/
  </code></pre>
  
  <p>Do you know what might be causing this error?</p>
  
  <hr>
  
  <p>Edit: With <code>pip3</code> it behaves the same.</p>
  
  <pre><code>$ sudo -H pip3 install --upgrade tensorpack
  Collecting tensorpack
    Using cached tensorpack-0.1.7-py2.py3-none-any.whl
  Collecting msgpack-numpy (from tensorpack)
    Using cached msgpack_numpy-0.3.9-py2.py3-none-any.whl
  Collecting pyzmq (from tensorpack)
    Using cached pyzmq-16.0.2-cp35-cp35m-manylinux1_x86_64.whl
  Collecting functools32 (from tensorpack)
    Using cached functools32-3.2.3-2.zip
      Complete output from command python setup.py egg_info:
      This backport is for Python 2.7 only.
  
      ----------------------------------------
  Command "python setup.py egg_info" failed with error code 1 in /tmp/pip-build-ut16f9e3/functools32/
  </code></pre>