Should throw better errors when using invalid chart type

[awsmsrc]

I copied the parseRawData example for my app which used a chartType of 'metric'
I switched this to 'line' it should have been 'linechart' (My fault rtfm)

I got a pure js error Uncaught TypeError: Cannot read property 'initialize' of undefined (line number 4680)

It would have been nice (and a timesaver) to have a more appropriate error message

[dustinlarimer]

👍 good call, @awsmsrc - thanks for the suggestion! We'll add some messaging around this over the next few patch releases.