Create a function in gw_data_stats.py called
make_bin_quantile. The function creates a python dataframe with
time indices and columns as each circuit and mains.
Function allow used to define time bin size then it finds the desired
quantile of energy demand.
i.e make_bin_quantile(SD_wh,'Q', 0.90') would express the 90th quantile
energy demand day inside of each quarter for all circuits