uvt-kvm ssh fails with No such file or directory: u'/var/lib/libvirt/dnsmasq/default.leases'

`uvt-kvm ssh --insecure <VM>` fails, but I can ssh to the VM using IP address instead.

$ uvt-kvm create ssh-test release=trusty

$ uvt-kvm ssh --insecure ssh-test
Traceback (most recent call last):
  File "/usr/bin/uvt-kvm", line 35, in <module>
    uvtool.libvirt.kvm.main_cli_wrapper(sys.argv[1:])
  File "/usr/lib/python2.7/dist-packages/uvtool/libvirt/kvm.py", line 711, in main_cli_wrapper
    main(*args, **kwargs)
  File "/usr/lib/python2.7/dist-packages/uvtool/libvirt/kvm.py", line 706, in main
    args.func(parser, args)
  File "/usr/lib/python2.7/dist-packages/uvtool/libvirt/kvm.py", line 582, in main_ssh
    return ssh(name, login_name, args.ssh_arguments)
  File "/usr/lib/python2.7/dist-packages/uvtool/libvirt/kvm.py", line 467, in ssh
    ips = name_to_ips(name)
  File "/usr/lib/python2.7/dist-packages/uvtool/libvirt/kvm.py", line 460, in name_to_ips
    in (uvtool.libvirt.mac_to_ip(mac) for mac in macs)
  File "/usr/lib/python2.7/dist-packages/uvtool/libvirt/kvm.py", line 460, in <genexpr>
    in (uvtool.libvirt.mac_to_ip(mac) for mac in macs)
  File "/usr/lib/python2.7/dist-packages/uvtool/libvirt/__init__.py", line 241, in mac_to_ip
    with codecs.open(LIBVIRT_DNSMASQ_LEASE_FILE, 'r') as f:
  File "/usr/lib/python2.7/codecs.py", line 878, in open
    file = __builtin__.open(filename, mode, buffering)
IOError: [Errno 2] No such file or directory: u'/var/lib/libvirt/dnsmasq/default.leases'

ProblemType: Bug
DistroRelease: Ubuntu 15.04
Package: uvtool-libvirt 0~bzr92-0ubuntu2
ProcVersionSignature: Ubuntu 3.18.0-13.14-generic 3.18.5
Uname: Linux 3.18.0-13-generic x86_64
ApportVersion: 2.16-0ubuntu1
Architecture: amd64
CurrentDesktop: Unity
Date: Tue Feb 10 16:45:32 2015
EcryptfsInUse: Yes
InstallationDate: Installed on 2015-02-09 (0 days ago)
InstallationMedia: Ubuntu 15.04 "Vivid Vervet" - Alpha amd64 (20150207)
PackageArchitecture: all
SourcePackage: uvtool
UpgradeStatus: No upgrade log present (probably fresh install)