* Added in-memory cache back (12, loganasherjones)
* Added support for TTL of messages (loganasherjones)
* Minor Python3 compability fixes
* Implement AsynchronousLogstashHandler::flush method
to manually flushed queued events (15, Vladislav Pakhomov)
* Ease modification of constants from the calling application (14)
* Add Formatter parameter 'ensure_ascii' to workaround potential
encoding errors on some setups (9, Sergei Lobastov)
For details see https://pypi.python.org/pypi/python-logstash-async/1.3.0