Add BlueButton support

[DaveDeCaprio]

We currently have a CSV file format for getting in claims data. Another useful format would be to take in data in FHIR JSON format. BlueButton is an example of a source like this. Example files are available for the BlueButton developer sandbox.

[DaveDeCaprio]

We'd like to have an option for run_predict that allows the predictor to take in data in BlueButton JSON FHIR format.