cmd/tsuru: update client version to 0.5

This version includes multiple changes related to multi-instance
support:

  - new commands unit-add and unit-remove
  - new parameter to app-create command (--units, to indicate how many
    units)
  - change app-info output to display information about units
  - change app-list output to display information about units
  - remove app information about app state from app-info output (there
    is no state in apps anymore)
cmd/tsuru: don't display IP of units in app-info

The IP of the unit is not really necessary :-)
api: require tsuru 0.5 :-)