No way to specify error bars on a ScatterTrace

[Traderjoe95]

plot.ly offers the opportunity to specify both, x and y error bars for scatter traces by using the error_x resp. error_y keys as can be seen here: https://plot.ly/python/reference/#scatter-error_x and here: https://plot.ly/python/reference/#scatter-error_y

Will they be available through the ScatterTrace builder? For the moment, I can manually hack that error bars into the JavaScript, but I'd rather see them as a part of tablesaw's API (which I think is really nice btw) as it is already part of plot.ly's API.

[lwhite1]

This should be added to the tablesaw api. We would welcome a PR if you have the time.