Adafruit-circuitpython-tca9548a

- needed when running on linux machines
- thanks StevenBruinen for this fix

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-tca9548a`.

Read the [docs](http://circuitpython.readthedocs.io/projects/tca9548a/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, `pip install adafruit-circuitpython-tca9548a`.

Read the [docs](http://circuitpython.readthedocs.io/projects/tca9548a/en/latest/) for info on how to use it.

- Added `setup.py`
- Added PyPI release info to `.travis.yml`
- Updated `requirements.txt`
- Added a more comprehensive `.gitignore`

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-tca9548a`.

Read the [docs](http://circuitpython.readthedocs.io/projects/tca9548a/en/latest/) for info on how to use it.

let there be multiplex!