Replace the console output on Error with fault a message

Trying to get the console log from an ERROR-ed server
does not really works

The console log does not contains any meaningful info
related to most status changes,
it is just what the instance prints to the serial console.

Only one action is guest assisted: the 'soft reboot',
which automatically switched to 'hard reboot'
when the guest forgets to assist
(ie. does not shutdown in 120 sec)

Testing the console output presence before reporting
active state would make more sense.

Instead of attempting to get the serial console output,
after this change the response 'fault' field will be used
for exception detail when available.

Closes-Bug: #1332414

This reverts commit c1a3bbe37c6202562fad5ff1be6e818d12797aee.

Change-Id: I2018f98cdc4a1bc7dd8f34833df228dc56d88a95
Correct volume type api schema validation

Volume type in api response body can be None, so add None value to
volume create and list api  schema validation.

Closes-bug: 1341924

Change-Id: I151b407ea2ec871375cbf96f41269fd8a5414a29
Refactor random url generation into its own method

Previously, endpoint URL were generated randomly before sending endpoint
requests to the Keystone server. Now that Keystone is validating input
on incoming requests, URLs have to match a regular expression in order
to be considered valid. This change makes the endpoint URLs compliant
for the endpoint request.

Change-Id: I365e651632fc4952a483655e51f3958598e059dd
Merge "Replace the console output on Error with fault a message"
Merge "Correct volume type api schema validation"
Merge "Refactor random url generation into its own method"
Merge branch 'master' of https://github.com/openstack/tempest