unreleased packages should not list as errors

[ssbarnea]

It is missleading to use red color to present packages that were not released yet. Maybe you could use yellow/orange to display them as their are clearly not out of version specifiers.

[eight04]

We should filter out prerelease from the version list around here:

pip-outdated/pip_outdated/check_outdated.py

Line 42 in 160c5b3

def get_pypi_versions(name, session=requests):

Something like:
https://github.com/eight04/vpip/blob/fd3a11c525a5b917ac2332458615db80d6ca0642/vpip/pypi.py#L40