Error when plotting smps.plots.heatmap

[dhhagan]

Discussed in #51

^{Originally posted by Ethan-Barber July 25, 2022}
When I copy the code for the sample "boston" example and plot the heatmap, I receive the error "Cannot cast ufunc 'greater_equal' input 0 from dtype('<m8[ns]') to dtype('<m8') with casting rule 'same_kind'". Any ideas how I can fix this?