Add UUIDs to all tempest tests and gate check

Adds uuid4 as a decorator of the form:
@test.idempotent_id('12345678-1234-1234-1234-123456789abc')
to every test in the Tempest tree. Includes a gate check to
ensure the existence and uniqueness of the ids.

Modify check tool to ignore Tempest unit tests.

Change-Id: I19e3c7dd555a3ea09d585fb9091c357a300e6559
Co-Authored-By: Sergey Slipushenko <sslypushenko@mirantis.com>
Implements: bp test-uuid
diff --git a/tox.ini b/tox.ini
index 475bea4..f3fc8b7 100644
--- a/tox.ini
+++ b/tox.ini
@@ -113,9 +113,11 @@
 commands =
    flake8 {posargs}
    {toxinidir}/tools/config/check_uptodate.sh
+   python tools/check_uuid.py
 
-[testenv:uuid]
-commands = python tools/check_uuid.py {posargs}
+[testenv:uuidgen]
+commands =
+   python tools/check_uuid.py --fix
 
 [hacking]
 local-check-factory = tempest.hacking.checks.factory