Add duplicate uuid checking for tempest tests

This patch adds a pep8 test for duplicate uuids in the tempest tests.
It also corrects some existing duplicates.

Change-Id: I2fc03b3cc604528903b8f70ce7f1e4e641aeafd2
diff --git a/tox.ini b/tox.ini
index 8854d21..86d81b1 100644
--- a/tox.ini
+++ b/tox.ini
@@ -18,7 +18,12 @@
   stestr slowest
 
 [testenv:pep8]
-commands = flake8
+commands =
+  flake8
+  check-uuid --package octavia_tempest_plugin
+
+[testenv:uuidgen]
+commands = check-uuid --fix --package octavia_tempest_plugin
 
 [testenv:venv]
 commands = {posargs}