check_schema_versions test fails with unclean reactor

While running tox -e parallel from current master, in my machine, i got the following error:

=============================================== FAILURES ================================================
________________ CouchStateTests.test_check_schema_versions_wrong_schema_version_raises _________________
[gw3] linux2 -- Python 2.7.13 /home/drebs/dev/leap/repos/soledad/.tox/parallel/bin/python2.7
NOTE: Incompatible Exception Representation, displaying natively:

DirtyReactorAggregateError: Reactor was unclean.
Selectables:
<<class 'twisted.internet.tcp.Client'> to ('127.0.0.1', 5984) at 7f3b451f0f90>