Scatter trace

[wangjiawen2013]

Hi,
All the scatter plot in the examples need the trace trait, which is not used now. So the the following error will occur, and the error message is meaningless:

We need use plotly::{Plot, Scatter, Trace} instead of use plotly::{Plot, Scatter}. Because other plots such as heatmap, contour don't need the Trace trait, how to fix it ?

[andrei-ng]

Thanks for the report, I will have a look and come back to you.