concert_simple_scheduler: improve documentation
Update with queue_size to avoid warnings in indigo

They just got the warning implemented for rospy publishers not specifying queue_size in indigo.

* http://lists.ros.org/pipermail/ros-users/2014-March/068333.html
* http://wiki.ros.org/rospy/Overview/Publishers%20and%20Subscribers

It's very spammy :neckbeard:
Update with queue_size to avoid warnings in indigo
Merge pull request #29 from stonier/patch-2

Update with queue_size to avoid warnings in indigo
concert_scheduler_requests: set queue_size=1 to minimize latency (#29)
doc: use nature theme for Sphinx
tag change logs for release