setuptools==0.6 can cause DistributionNotFound error while using peep.

[dean]

It shows the 'You don't have pip>=0.6.8' error, but it's caused by the DistributionNotFound error that's thrown.

There are a couple solutions:

1. Add a requirements file with setuptools>=0.9.8
2. Anytime setuptools < 0.9.8 is tried to be installed, throw an error and let the user know why.

I say setuptools>=0.9.8 because according to the docs[1] it's supposed to be backwards compatible with all previous setuptools versions.

[1] https://pypi.python.org/pypi/setuptools

[dean]

I ran into this error after installing setuptools==0.6c, for reference.