distribute installation breaks pip, fabric, etc.

[imiric]

Why are you including distribute 0.6.27 with this package? It makes no sense and is breaking pip and fabric after installing this package. For example:

$ fab
Traceback (most recent call last):
  File "/usr/local/bin/fab", line 5, in <module>
    from pkg_resources import load_entry_point
  File "build/bdist.linux-x86_64/egg/pkg_resources.py", line 2735, in <module>
    return mkstemp(*args,**kw)
  File "build/bdist.linux-x86_64/egg/pkg_resources.py", line 690, in require

  File "build/bdist.linux-x86_64/egg/pkg_resources.py", line 588, in resolve
    Unless `replace_conflicting=True`, raises a VersionConflict exception if
pkg_resources.DistributionNotFound: paramiko>=1.10

$ pip install paramiko
Downloading/unpacking paramiko
  Downloading paramiko-1.15.1-py2.py3-none-any.whl (165kB): 165kB downloaded
Cleaning up...
Exception:
Traceback (most recent call last):
  File "/usr/lib/python2.7/dist-packages/pip/basecommand.py", line 122, in main
    status = self.run(options, args)
  File "/usr/lib/python2.7/dist-packages/pip/commands/install.py", line 278, in run
    requirement_set.prepare_files(finder, force_root_egg_info=self.bundle, bundle=self.bundle)
  File "/usr/lib/python2.7/dist-packages/pip/req.py", line 1259, in prepare_files
    )[0]
IndexError: list index out of range

Storing debug log for failure in /root/.pip/pip.log

These all seem like bugs caused by using the old version of distribute found in this package. I don't see a reason to ever include distribute with your package which will overwrite the user's own, but perhaps I'm missing something.

[ncadou]

I actually used a packaging bootstrapping template this time around. Probably not the best of choices. I wonder in which circumstances including distribute breaks pip though, as the initial project that prompted building scrapy-webdriver in the first place was deployed using pip. Regardless, thanks for the pull request, I'll make sure to take a look ASAP.

[imiric]

Yeah, I didn't have this issue when I was using scrapy-webdriver within a virtualenv, but it appeared when I tried using it in Docker (without virtualenv). Presumably because it overwrites the system's distribute, though I can't say for sure. Nowadays distribute is merely a wrapper for setuptools anyway, so I think there's no harm in removing it from your package.

I didn't create a PR as I wasn't sure if you'd be interested, but it fixed the issue for me, so feel free to merge it in if you want. :)