Add fab task to update virtualenv
Add fab task to update virtualenv

Should eventually not run unconditionally but only when
requirements.txt file changes

wiki-ai/ores,aetilley/ores,aetilley/ores,wiki-ai/ores,aetilley/ores,wiki-ai/ores,he7d3r/ores,he7d3r/ores,he7d3r/ores