Adafruit-circuitpython-ble

- Update `DeviceInfoService` to use latest internal API. Allow it to query a remote service.

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

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

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

Fix packaging so that it finds sub-packages and remove use of mocks for testing. We rely on Blinka's _bleio stubs now.

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

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

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

Prevent plotter example from swamping Mu with input. Fixes 57. Thanks dglaude!

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

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

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

- Supply default HID descriptor for HIDService.
- Fix lazy advertising field instantiation; this fixes problems with advertising flags.
- Fix doc formatting.

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

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

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

This release includes:
* A fix to the way this library was packaged in PyPi. While this library is only supported for CircuitPython use, our CI wasn't able to import this as a dependency for another library.

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

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

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

Main Changes:
* ANCS (Apple Notification Center Service) now has its own repository, [Adafruit_CircuitPython_BLE_Apple_Notification_Center](https://github.com/adafruit/Adafruit_CircuitPython_BLE_Apple_Notification_Center)
* Magic Light also has its own repository, [Adafruit_CircuitPython_BLE_Magic_Light](https://github.com/adafruit/Adafruit_CircuitPython_BLE_Magic_Light)
* Apple Media Service (previously unimplemented) was also moved to its own repository, [Adafruit_CircuitPython_BLE_Apple_Media](https://github.com/adafruit/Adafruit_CircuitPython_BLE_Apple_Media)


Other changes:
* Repository was migrated from Travis to GitHub Actions
* Bug fixes