Adafruit-circuitpython-minimqtt

This release updates the library to use `time.monotonic_ns()` when it's available to avoid the imprecision that occurs with `time.monotonic()`. Thank you vladak. User code can pass `use_impercise_time=True` argument to the constructor to fallback to using `time.monotonic()`.

To use in CircuitPython, simply install the [Adafruit CircuitPython Bundle](https://circuitpython.org/libraries).

To use in CPython, `pip3 install adafruit-circuitpython-minimqtt`.

Read the [docs](https://circuitpython.readthedocs.io/projects/adafruit-circuitpython-minimqtt/en/latest/) for info on how to use it.

This release changes what was previously `client._user_data` to be `client.user_data` with no leading underscore, to denote that it is part of the intended public API for code outside of this class to access as needed. Thank you vladak

To use in CircuitPython, simply install the [Adafruit CircuitPython Bundle](https://circuitpython.org/libraries).

To use in CPython, `pip3 install adafruit-circuitpython-minimqtt`.

Read the [docs](https://circuitpython.readthedocs.io/projects/adafruit-circuitpython-minimqtt/en/latest/) for info on how to use it.

This release properly raises an exception if `loop()` is called when the mqtt client is not connected. Thank you vladak

To use in CircuitPython, simply install the [Adafruit CircuitPython Bundle](https://circuitpython.org/libraries).

To use in CPython, `pip3 install adafruit-circuitpython-minimqtt`.

Read the [docs](https://circuitpython.readthedocs.io/projects/adafruit-circuitpython-minimqtt/en/latest/) for info on how to use it.

This release removes an unused argument from the on_message handler. Thank you vladak.

To use in CircuitPython, simply install the [Adafruit CircuitPython Bundle](https://circuitpython.org/libraries).

To use in CPython, `pip3 install adafruit-circuitpython-minimqtt`.

Read the [docs](https://circuitpython.readthedocs.io/projects/adafruit-circuitpython-minimqtt/en/latest/) for info on how to use it.

To use in CircuitPython, simply install the [Adafruit CircuitPython Bundle](https://circuitpython.org/libraries).

To use in CPython, `pip3 install adafruit-circuitpython-minimqtt`.

Read the [docs](https://circuitpython.readthedocs.io/projects/adafruit-circuitpython-minimqtt/en/latest/) for info on how to use it.

Added test code for basic `loop()` functionality. Thanks vladak!

To use in CircuitPython, simply install the [Adafruit CircuitPython Bundle](https://circuitpython.org/libraries).

To use in CPython, `pip3 install adafruit-circuitpython-minimqtt`.

Read the [docs](http://circuitpython.readthedocs.io/projects/minimqtt/en/latest/) for info on how to use it.