In Neutron we hit quite often same issue as Manila, see [1] for
details.
It looks that solution for this problem may be increase timeout
for test_walk_version functional tests.
Higher timeout will be applied for tests for both pgsql and mysql
backends but it is mostly needed for mysql because 'pymysql' works
much slower on slow nodes than 'psycopg2'
This patch adds also new decorator to set individual timeout for
tests.
[1] https://bugs.launchpad.net/manila/+bug/1501272
Change-Id: I5f344af6dc3e5a6ee5f52c250b6c719e1b43e02d
Closes-Bug: #1687027
(cherry picked from commit c2c37272bf)
026d911832