Not Real - Hooking In Sounds Review

@kadst43 - Not a real commit, just looking for guidance/scolding on placement of sounds and referencing the soundManager. Sounds are playing though! (Weird stuff happening with the diff in scenario.js - dunno what's up with that.)
I'd make this an array, not an object.  

roverSounds = [];
roverSounds.push(...); // add roverSounds[0]
roverSounds.push(...); // add roverSounds[1]