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/tempest/api/compute/admin/test_security_groups.py b/tempest/api/compute/admin/test_security_groups.py
index 82cb26e..19f5b8c 100644
--- a/tempest/api/compute/admin/test_security_groups.py
+++ b/tempest/api/compute/admin/test_security_groups.py
@@ -37,6 +37,7 @@
         else:
             self.client.delete_security_group(securitygroup_id)
 
+    @test.idempotent_id('49667619-5af9-4c63-ab5d-2cfdd1c8f7f1')
     @testtools.skipIf(CONF.service_available.neutron,
                       "Skipped because neutron do not support all_tenants"
                       "search filter.")