Use the glance_image module from Ansible core
Add the cirros 0.3.0 test image

It takes 60 seconds to boot, 40 seconds less than 0.3.1.
But 0.3.1 has curl with https support.
Disable libvirt file injection

There is a problem with qemu-nbd where it never completes and hogs the cpu.
This feature is not needed as the keys etc can be got from the metadata
service.