PPA support

[noplay]

It's not really an issue but I document it for people who want to build with dh-virtualenv on Ubuntu ppa. The main issue is ppa builder doesn't have access to the internet when building from the source package. The trick is to cache package in the source file uploaded to PPA and use this cache instead of PyPi.

1. Add the dh-virtualenv ppa as dependencies of your ppa
2. Download pip package to your local computer

mkdir debian/pypi
pip3 install  --download debian/pypi -r requirements.txt

3. Edit your rules file for something like that:

#!/usr/bin/make -f

%:
    dh $@ --with python-virtualenv

override_dh_virtualenv:
    dh_virtualenv --extra-pip-arg "--no-index" --extra-pip-arg "--find-links=file://${PWD}/debian/pypi

[nailor]

This is pretty great, good tips :)

I'm looking into (finally) creating the tips and tricks section to the documentation, this could be included there. I'll leave the issue open until it is documented somewhere :)