Bug in ScalesimReport load_detail_report_data()

In scalesim/utilities/scalesim_report.py load_detail_report_data():

` def load_detail_report_data(self, data_dir='.', run_name=''):
        csv_filename = data_dir + '/' + run_name + '/DETAILED_ACCESS_REPORT.csv'
        self.bandwidths_df = pd.read_csv(csv_filename, sep=r'\s*,\s*', engine='python')
        self.details_df_ready = True
`

I think `self.band_widths.df` should be `self.details_df`