Fix Python 2.7-ism in pulsar/managers/stateful.py.
Fix Python 2.7-ism in pulsar/managers/stateful.py.

jmchilton/pulsar,ssorgatem/pulsar,natefoo/pulsar,jmchilton/pulsar,galaxyproject/pulsar,galaxyproject/pulsar,natefoo/pulsar,ssorgatem/pulsar