Python Support

The latest pip patch version updated a dependency that changes how `.` is normalized in package names. Unfortunately this causes issues with pulp_python and similar tools (such as devpi). We can confirm that our pulp is affected by attempting to install the package `zope.interface`. This works correctly with pip 8.1.1, but fails with pip 8.1.2, which claims the package can't be found in the index.

See https://github.com/pypa/pip/issues/3666 for the issue with pip where this is discussed; the maintainers have closed the issue, and are taking the stance that tools like devpi and pulp will need to be updated to fix.

Currently, we've worked around the issue by pinning pip==8.1.1, but this is a short-term fix.

Let me know if I can provide any additional information. Thanks!