Add support for creating/playing songs

[jacobperron]

Already supported in the underlying library (https://github.com/AutonomyLab/libcreate), just need to expose at the ROS API level.

[clydemcqueen]

Hi, are you interested in help on this? I have a simple solution up and running.

[jacobperron]

Pull requests are welcome 👍

[clydemcqueen]

#37