Add missing packages

-redir
-should install qemu before libvirt.

Signed-off-by: Hiroshi Miura <miurahr@linux.com>
remove box comment

- Vagrant now only support ruby2.0 and after.
  We should use distro version with ruby 2.0.

Signed-off-by: Hiroshi Miura <miurahr@linux.com>
README: spec example and Ruby2.0

- change spec run example as same as travis.yml
- add description about target Ruby version 2.0

Signed-off-by: Hiroshi Miura <miurahr@linux.com>