cli: expose api capabilities in cli #891227

== Usage ==

capabilities [command options]

== Description ==

Displaying system capabilities for the given version.

== Arguments ==

 * [features] - Lists version features.

Bug-Url: https://bugzilla.redhat.com/show_bug.cgi?id=891227
Change-Id: I501739820951cdccdad16013b0de761ca2e276cd
Signed-off-by: Michael pasternak <mpastern@redhat.com>