Add @test.attr(type='slow') to slow tests to reduce test run time.

Currently, there are a few tests, predominantly compute and volume
tests, that run very slowly. These include tests like
test_revert_resize_server in compute which takes almost 4 minutes
to run as well as test_volume_backup_export which takes almost
30 seconds to run [0].

This patch adds @test.attr(type='slow') decorator above these
slow tests (tests whose run time is >= 30 seconds or very
close to 30 seconds).

This means that the regex in post_test_hook can be modified
to be '(?!.*\[.*\bslow\b.*\])(^patrole_tempest_plugin\.tests\.api)',
similar to how Tempest does it already [1].

[0] http://logs.openstack.org/38/443238/2/check/gate-tempest-dsvm-patrole-admin-ubuntu-xenial-nv/222bfda/console.html
[1] https://github.com/openstack/tempest/blob/master/tox.ini

Change-Id: Ib7bf72a9a6cef79d9d54b0b9dea53338f708ba30
Partially-Implements: blueprint decrease-tempest-gate-runtime
3 files changed