Release v3.2.0b1

Added

• Added Stop.NONE as then option for motors. This allows subsequent
  motor and drive base commands to transition without stopping.
• Added Stop.COAST_SMART as then option for motors. This still coasts the
  motor, but it keeps track of the previously used position target. When a new
  relative angle command is given (e.g. rotate 90 degrees), it uses that
  position as the starting point. This avoids accumulation of errors when using
  relative angles in succession.
• Made motor deceleration configurable separately from acceleration.
• Enabled ujson module.
• Added ability to use more than one DriveBase in the same script.
• Added support for battery charging on Prime and essential hubs.

Changed

• Changed how DriveBases and Motor classes can be used together.
  Previously, an individual motor could not be used when a drive base used it.
  From now on, devices can always be used. If they were already in use by
  something else, that other class will just be stopped (coast).
• Changed how unexpected motor problems are handled, such as a cable being
  unplugged while it was running. Previously, this raised a SystemExit no
  matter which motor was unplugged. Now it will return an OSError with
  ENODEV, which is consistent with trying to initialize a motor that isn't
  there. The Motor class must be initialized again to use the motor again.
• Changing settings while a motor is moving no longer raises an exception. Some
  settings will not take effect until a new motor command is given.
• Disabled Motor.control and Motor.log on Move Hub to save space.
• Changed LED color calibration on Prime hub to make yellow less green.
• Updated to upstream MicroPython v1.18.
• Changed imu.acceleration() units to mm/s/s (pybricks-micropython#88) for
  Move Hub, Technic Hub, and Prime Hub.

Fixed

• Fixed color calibration on Powered Up remote control (support#424).
• Fixed 3x3 Light Matrix colors with hue > 255 not working correctly (support#619).