Nicole/meter metadata

[nicolemah99]

Update metadata to look like:

event_id: 
event_timestamp:
meter_id:
meter_type:
data_level:
download_start:
download_end: 
download_time: 
download_speed: 
total_files_size: 

files:
  - file_name:
    md5: 
  - file_name:
    md5: 
  - file_name:
    md5: 
  - file_name:
    md5: 
  - file_name:
    md5: