Adafruit-circuitpython-trellism4

Added ability to set `trellis.pixels.auto_write = False` and then call `trellis.pixels.show()` following NeoPixel code.

Thanks adammhaile for this addition!

To use in CircuitPython, simply install the [Adafruit CircuitPython bundle](https://github.com/adafruit/Adafruit_CircuitPython_Bundle).

To use in CPython, `pip3 install adafruit-circuitpython-trellism4`.

Read the [docs](http://circuitpython.readthedocs.io/projects/trellism4/en/latest/) for info on how to use it.

To use in CircuitPython, simply install the [Adafruit CircuitPython bundle](https://github.com/adafruit/Adafruit_CircuitPython_Bundle).

To use in CPython, `pip3 install adafruit-circuitpython-trellism4`.

Read the [docs](http://circuitpython.readthedocs.io/projects/trellism4/en/latest/) for info on how to use it.

Fixed issue where button coordinates were incorrect at `0` and `180` degree rotations. Added checks to prevent use of non-existent coordinates for NeoPixels.

For PyPI:
- Added `setup.py`
- Added PyPI release info to `.travis.yml`
- Updated `requirements.txt`
- Added a more comprehensive `.gitignore`
- Updated `README` with PyPI install instructions

To use in CircuitPython, simply install the [Adafruit CircuitPython bundle](https://github.com/adafruit/Adafruit_CircuitPython_Bundle).

To use in CPython, `pip install adafruit-circuitpython-trellism4`.

Read the [docs](http://circuitpython.readthedocs.io/projects/trellism4/en/latest/) for info on how to use it.

Removes the acceleration property and related example.

The library used for the accelerometer on the chip is new and will be undergoing API changes. Once that is settled, the `acceleration` feature will be implemented in this lib.

To use in CircuitPython, simply install the [Adafruit CircuitPython bundle](https://github.com/adafruit/Adafruit_CircuitPython_Bundle).

Read the [docs](http://circuitpython.readthedocs.io/projects/trellism4/en/latest/) for info on how to use it.

- Added `acceleration` property! See documentation for usage.
- Added acceleration example.

To use in CircuitPython, simply install the [Adafruit CircuitPython bundle](https://github.com/adafruit/Adafruit_CircuitPython_Bundle).

Read the [docs](http://circuitpython.readthedocs.io/projects/trellism4/en/latest/) for info on how to use it.

This high level library provides objects that represent Trellis M4 hardware. It allows you to address the buttons and NeoPixels in a grid using coordinates (i.e. `(0, 1)`), and provides much of the same functionality available from the NeoPixel library.

To use in CircuitPython, simply install the [Adafruit CircuitPython bundle](https://github.com/adafruit/Adafruit_CircuitPython_Bundle).

Read the [docs](http://circuitpython.readthedocs.io/projects/trellism4/en/latest/) for info on how to use it.