Remove a few tests from multinode gate

The multinode gate is reserved for tests that require multiple nodes
like server migration tests. It is also used for slow-running
tests that take a while to execute (20-30+ seconds) to better
parallelize tests in the gates.

However, 3 tests currently meet neither of these criteria and are
hence being moved to the voting gates:

  * test_create_security_group_for_server [6.492102s]
  * test_remove_security_group_from_server [6.525612s]
  * test_volume_upload_public [4.558483s]

Change-Id: I24c65839692264f30a1494c051eec5fb72eb78a6
Source: http://logs.openstack.org/68/494368/12/check/gate-tempest-dsvm-patrole-multinode-member-ubuntu-xenial-nv/32ae39c/console.html
2 files changed