This build keeps timing out on Travis and it's unlikely including the
additional guest front-ends will catch any failures in the fallback
code.

Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
Acked-by: Stefano Garzarella <sgarzare@redhat.com>
Reviewed-by: Wainer dos Santos Moschetta <wainersm@redhat.com>