Update the "os availability zone list" command to support listing
network availability zones along with the currently listed compute
and volume availability zones. This adds the --network option to
the command in order to only list network availability zones. By
default, all availability zones are listed. The --long option
was also updated to include a "Zone Resource" column which is
applicable to network availability zones. Example zone resources
include "network" and "router".
If the Network API does not support listing availability zones
then a warning message will be issued when the --network option
is specified.
This support requires an updated release of the SDK in order
to pull in [1].
[1] https://bugs.launchpad.net/python-openstacksdk/+bug/1532274
Change-Id: I78811d659b793d9d2111ea54665d5fe7e4887264
Closes-Bug: #1534202