Survey JSON spec

There are two types of surveys: Audio Surveys (a.k.a. voice recording surveys) and Tracking Surveys (questionnaires).

Researchers can edit surveys in the Beiwe web interface, and those surveys are saved as JSON survey specification files which the phones then download. Here are example JSON survey specifications:

{'_id': ObjectId('5aa1db2b2797c12c72095d7c'),
 'survey_type': 'audio_survey',
 'timings': [[28800],
             [61200],
             [61200],
             [61200],
             [61200],
             [61200],
             [28800, 61200, 81000]],
 'content': [{'prompt': "Please read this voice recording prompt out loud.  When you're done, press the Save button."}],
 'settings': {'audio_survey_type': 'raw',
              'sample_rate': 22050,
              'trigger_on_first_download': False}}