Ensure availability command output.
Report result type error.
Json encoding specifiers for api structs.
Rename EnsureAvailabilityParams to StateServersSpec.
Rename EnsureAvailabilityResult to StateServersChange.
State EnsureAvailability call returns changes structure.
Added promotion and demotion information to ensure-availability output.
Tag-Id separation in ensure-availability.
Tags instead of ids.
Minor cleanup.
Do not quote machine names.
Updates w.r.t new names package api.
Merge pull request #39 from tasdomas/ensure-availability-output

Ensure availability command output.

Add output for ensure-availability command.

The ensure-availability command will notify the user, how many state servers
were added to the environment.

$ juju ensure-availability -n 7
maintaining machines: "0"
adding machines: "1", "2", "3", "4", "5", "6"

This is a move to github of the MP started in https://codereview.appspot.com/99670044/