- update to 3.1.5:
* fix: do not block when process exits not correctly
* fix: typo in stdout handling
* fix: typo in stdout handling
* fix: remove universal tag since Python 2 is not supported anymore
* fix: close devnull
* fix: do not leave zombie process
* Fix broken Ceph config formatting
* chore: compress image
* Add Ceph Nautilus and later support
* ceph: set limit for max open fds
* Add TLS\_ENABLED environment var for memcached
* Add Python 3.7 and 3.8 to classifier
* Fix import ordering
* Remove Python 2.x support and six
* Fix zookeeper driver
* Disable aodh for py27 too
* Tidy up tox.ini and update kafka
* Fix tests and add recent Python releases
* Try to fix PEP8 again
* Various fixes
* Add a driver for httpbin
* Update README.rst : Fix typo access
* fix: log info, not error when command is ready
* Fixes flake8 warning and adds missing comma
* Apply suggestions from code review
* Add TLS params to memcached
* Add ceph-manager support
* Add Ceph config options for small disks