ci: test with and without ujson
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
Install Tornado via rosdep

Use python-tornado-pip to make sure we get the speedups introduced in Tornado 3.2.
Merge pull request #136 from EndPointCorp/rosdep_tornado

Install Tornado via rosdep
updated changelog
0.6.6
Revert "Install Tornado via rosdep"

This reverts commit 2d8a2fa5d23550427d6957acffc7dfa6f55e9c34.
Merge pull request #137 from RobotWebTools/revert

Revert "Install Tornado via rosdep"
updated package manifests
changelogs updated
0.6.7
add a lock to calls to load_manifest - apparently, it's not thread safe

fixes #108