Retaining defaults from xarray

Hello, all, I'm beginning to use this package and I think it works extremely well. However, one small thing I miss but that makes a lot of difference is `xarray`'s default selection when plotting. Baically when `xarray` detects that a data set has both positive and negative values it chooses a divergent colormap and adjusts the limits of the plot so that the colormap is symmetric around zero. This sounds silly but it makes a huge difference in my day-to-day life.

Here's [an example of what I mean](https://pasteboard.co/IdxZwnE.png). The default setting of matplotlib are much nicer, and it saves me from "polluting" the command with lots of lengthy keyword arguments. Is there a way to plot with `hvplot` but keeping `xarray` defaults? If not, please consider this a feature request.

Thanks!