title: pip fails with AttributeError: 'module' object has no attribute 'wraps'
body: <p>I'm on Fedora. I recently upgraded my system from F20 to F21. Pip was working fine on F20 but after the upgrade to F21 something must have gone wrong. Pip stopped working, every time I enter the command <code>pip &lt;anything&gt;</code> the error below occurs:</p>
  
  <pre><code>Traceback (most recent call last):
    File "/usr/bin/pip", line 7, in &lt;module&gt;
      from pip import main
    File "/usr/lib/python2.7/site-packages/pip/__init__.py", line 12, in &lt;module&gt;
      from pip.commands import commands, get_summaries, get_similar_commands
    File "/usr/lib/python2.7/site-packages/pip/commands/__init__.py", line 6, in &lt;module&gt;
      from pip.commands.bundle import BundleCommand
    File "/usr/lib/python2.7/site-packages/pip/commands/bundle.py", line 6, in &lt;module&gt;
      from pip.commands.install import InstallCommand
    File "/usr/lib/python2.7/site-packages/pip/commands/install.py", line 5, in &lt;module&gt;
      from pip.req import InstallRequirement, RequirementSet, parse_requirements
    File "/usr/lib/python2.7/site-packages/pip/req/__init__.py", line 3, in &lt;module&gt;
      from .req_install import InstallRequirement
    File "/usr/lib/python2.7/site-packages/pip/req/req_install.py", line 31, in &lt;module&gt;
      from pip.utils import (
    File "/usr/lib/python2.7/site-packages/pip/utils/__init__.py", line 59, in &lt;module&gt;
      def rmtree(dir, ignore_errors=False):
    File "/usr/lib/python2.7/site-packages/pip/_vendor/retrying.py", line 47, in wrap
      @six.wraps(f)
  AttributeError: 'module' object has no attribute 'wraps'
  </code></pre>