title: Install Bash completion together with distutils / pip
body: <p>I have created a simple Python module and want to distribute it with pip. I also want to install a Bash completion file together with the module.
  I'm installing the module with Python 2.7.1+ and pip 0.8.2.</p>
  
  <p>I have this setup.py:</p>
  
  <pre><code>setup(
      name='jenkinsmon',
      version='0.0.1',
      description='Jenkins Job Monitor',
      long_description=open('README.txt').read(),
      scripts=['bin/jenkinsmon'],
      data_files=[
          ('/etc/bash_completion.d', ['extras/jenkinsmon.completion']),
      ],
      install_requires = [
          'autojenkins',
          'argparse'
      ],
  )
  </code></pre>
  
  <p>Now if I try to install the package with <code>pip install -e .</code>, the Bash completion file never gets installed together with the package.
  I also tried workarounds by specifying a MANIFEST.in, like described <a href="https://stackoverflow.com/questions/2994396/python-distutils-does-not-include-data-files">here</a>:</p>
  
  <p>MANIFEST.in:</p>
  
  <pre><code>include extras/jenkinsmon.completion
  </code></pre>
  
  <p>But this also doesn't help - the completion files won't get installed.
  What can I do to install the Bash completion files? </p>