Add tox -e zuul prerequisites

Manual installation of some basic packages is needed for tox -e zuul,
otherwise you'll get the following errors:

unable to execute 'x86_64-linux-gnu-gcc': No such file or directory
netifaces.c:1:20: fatal error: Python.h: No such file or directory

Change-Id: If112637e70db88dcf91b30f0d564f180633f92bf