* Now processes iAWE (just about!)
* implemented Electricity.drop_duplicate_indicies
* changes sample_period_multiplier from 4 to 20 in
  proportion_of_energy_submetered
* increased HEADROOM from 1.1 to 1.2 in get_dropout_rate
* fixed bug in get_dropout_rate where we didn't return the
  final processed value
* adding some more debug printing
* added more pre-processing for iAWE