[ocean] Some primitive property mappings fail (camel cased v. hypenated properties)

[alvinwan]

I saw #52 but that appears to not address camel-cased properties. I'm working with a-ocean and found that amplitudeVariance did not appear to change visibly, when I updated it:

1. For this primitive, the ocean should be completely still if amplitude = amplitudeVariance = speed = speedVariance = 0. Here's a simple example where all are zero and yet, the ocean still moves: http://jsfiddle.net/wz02xybp/1/. I tried hyphenated and all-lowercase versions of the property name as well (in case I just misunderstood)
2. I copied and pasted the a-ocean source in and found that data.amplitudeVariance wasn't being updated. http://jsfiddle.net/wz02xybp/2/ (I console.log(data.amplitudeVariance...)
3. However, if I change the mapping to amplitudevariance (all lowercase, http://jsfiddle.net/wz02xybp/3/) or amplitude-variance (hypenated, http://jsfiddle.net/wz02xybp/4/), all is well.

Does this look about right? Or have I simply misinterpreted an AFRAME mapping convention (e.g., amplitudeVariance actually means to use variance-amplitude)? Happy to make a PR if appropriate.