Adafruit-circuitpython-lis2mdl

We have upgraded Pylint checks to use the latest version of Pylint and implemented usage of Black Python formatting. This does not change the functionality of the code - it is designed to bring it up to current standards and make it more readable.

* Remove pinned Pylint version number from build.yml file
* Synced `.pylintrc` file to match Adafruit standard
* Ran upgraded Pylint and applied any changes or new disables necessary
* Ran Black formatter and allowed application of changes across entire repo

For more information on using Pylint and Black on your code, check out [this guide on working with Pylint and Black](https://learn.adafruit.com/improve-your-code-with-pylint)

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

To use in CPython, `pip3 install adafruit-circuitpython-lis2mdl`.

Read the [docs](http://circuitpython.readthedocs.io/projects/lis2mdl/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-lis2mdl`.

Read the [docs](http://circuitpython.readthedocs.io/projects/lis2mdl/en/latest/) for info on how to use it.

This release includes:
* Migrating this repository from Travis to GitHub Actions. This has no effect on the behavior of the code itself.

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

To use in CPython, `pip3 install adafruit-circuitpython-lis2mdl`.

Read the [docs](http://circuitpython.readthedocs.io/projects/lsm303agr_mag/en/latest/) for info on how to use it.

This release includes
* a rename of the former Adafruit_CircuitPython_LSM303AGR_Mag to the proper name of said mag sensor, the LIS2MDL
* Breaking changes! Everything works the same but the names are all different!

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

To use in CPython, `pip3 install adafruit-circuitpython-lis2mdl`.

Read the [docs](https://circuitpython.readthedocs.io/projects/lis2mdl/en/latest/) for info on how to use it.

This release includes
* reading `magnetic` values
* basic tuning parameters
* basic interrupt support

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

To use in CPython, `pip3 install adafruit-circuitpython-lsm303agr-mag`.

Read the [docs](https://circuitpython.readthedocs.io/projects/lsm303agr-mag/en/latest/) for info on how to use it.