Add combined_data instance variable and calculate on initialization of Pedometer
Add a simple low pass filter
Clean
Parse gravitational data as well as pure accelerometer data
Implement filter
Add DeviceData model and move all data related tasks to it
Offload all data calls to DeviceData instance on Pedometer
Clean
Clean
Add edge detection to pedometer, and tests with real data
Step count as an average of both positive and negative edges
Test
Add TODO
Refactor into one split_on_threshold method
Clean