change location of virtualenv dir inside container
change location of virtualenv dir inside container

there were permissions errors appearing when the .tox dir would
be written to by root from inside the container and another user
(jenkins) tried to remove the same files later.

Yelp/paasta,somic/paasta,gstarnberger/paasta,gstarnberger/paasta,Yelp/paasta,somic/paasta