ci: test with and without ujson
add backports to setup.py, so backports.ssl_match_hostname can be properly resolved
Change the behavior of MessageHandler.transition()

Now reflects usage in the tests, i.e. a QueueMessageHandler only needs queue_length to be defined, not throttle_rate.
modify tests

less duplicated code, some other changes to (hopefully) improve reliability. Tested locally about 30 times without encountering any failures.
Merge pull request #127 from megawac/uci

ci: test with and without ujson
Merge pull request #131 from T045T/package_backports

add backports to setup.py
update changelog
0.6.4
Merge pull request #133 from T045T/test_improvements

Test improvements
changelog updated
0.6.5
Merge branch 'develop' of github.com:RobotWebTools/rosbridge_suite
Merge branch 'master' of github.com:RobotWebTools/rosbridge_suite