set shell for default ubuntu user to /bin/bash

config/cloud.cfg

@@ -82,6 +82,7 @@ system_info:
      lock_passwd: True
      gecos: Ubuntu
      groups: [adm, audio, cdrom, dialout, floppy, video, plugdev, dip, netdev]
+     shell: /bin/bash
    # Other config here will be given to the distro class and/or path classes
    paths:
       cloud_dir: /var/lib/cloud/