chart data updator bug

[SamiSammour]

Hi there,
there is a problem when updating the chart when the new data length is less than the previous one.
for example if you have the dataset.data.length = 10 then the new dataset.data.length = 3 the chart first 3 points is updated but the rest are still drawn.

[sbatson5]

I experience this issue with line charts as well. For example:

Then updating the number of years we chart:

So my array of datapoints has changed length and I would want the whole chart to redraw. However, there may be use cases where you want to only update the first few data points. Would it make sense to add a property that forces redraw?

{{ember-chart type="Line" data=chartData options=chartOptions forceRedraw=true width=500 height=300}}

Or something to that effect?

[sbatson5]

@aomran I wrote another PR which should address this. The issue is that if the number of points for an item changes, the chart won't redraw since we are still charting the same number of datasets. PR with unit test is here:
#37

[aomran]

pull request #37 was merged -- that might address this

[aomran]

Closing this issue since it's been a while and the next major version is being worked on here: #54.