Create separate class to read list of fires from config, fetch data, and add updated data to data store

• "FlowAlert.get_new_data()"?

The following discussion from !11 (merged) should be addressed:

• @jmfee started a discussion:

  I was thinking update would happen in another module. datastore can read/write/merge data. Something else would read the list of configured fires, request new rain data, and add to the datastore?