of-flow: flow present in operational db even aftrer 60 seconds from switch removal

This bug might be related to https://bugs.opendaylight.org/show_bug.cgi?id=1654, but in my case you dont need to have 100s of flows configured.

See results from https://jenkins.opendaylight.org/integration/job/integration-master-verify-test-base-of13/138/robot/report/log.html

All 8 failures are flows which are present in operational db 30 seconds after deletion. I manually reproduced this behavior with 60 seconds delay too.

To reproduce use tests from this gerrit
https://git.opendaylight.org/gerrit/#/c/10256/
and run
pybot -v CONTROLLER:<ip> -v MININET:<ip> -v USER_HOME:$HOME -v MININET_USER:mininet ./csit/suites/base-of13/200__Flows_OF13_Stat_Manager/

You can manually increase the delay after deletion by modifying 010_SM_add_upd_del_flows.txt; Test Delete Flows; increase sleep timeout.