LogAndStream_Shimmer3_BLE_v0.16.013

What's Changed

• SHIM3-377 Python unit tests for new BT commands by @marknolan in #31
• DEV-92 initialising calib file names to null by @marknolan in #35

Full Changelog: LogAndStream_Shimmer3_BLE_v0.16.012...LogAndStream_Shimmer3_BLE_v0.16.013