Feature request: Support for plotting pint scalars

[hdavid16]

I love the figures generated with plotly. I want to use it as the backend for a Pandas dataframe that has units of measurement using (Pint). Unfortunately, these plots fail with the error:

AttributeError: 'float' object has no attribute 'tolist'

It seems that the issue is that Plotly is not recognizing Pint scalars as scalars. A MWE example is given on the following pint-pandas issue.

Thanks.