Add support for consumer-grade activity trackers #168
Description
Goal
Enable the import of data from consumer-grade activity trackers as a proxy for activity. The utility of such data was shown in a comparison between Fitbit Inspire 2/HR and MotionWatch 8 for non-parametric circadian rhythm analysis.
Current Behavior
There is currently no such option.
Expected Behavior
Import the data from a consumer-grade activity tracker using the same syntax as for the actigraphy devices.
Proposed Solution Approach
Extend pyActigraphy/io/* with utility functions to import the data. Start with Fitbit devices.