automation: increase root volume size on Linux
It is close to full in the AMI. I actually ran out of space running
tests without increasing the volume size!
Differential Revision: https://phab.mercurial-scm.org/D6716
# name space package to host third party extensionsfrom__future__importabsolute_importimportpkgutil__path__=pkgutil.extend_path(__path__,__name__)