Fix setup.py by removing DESCRIPTION.rst file access.

[bhjelstrom]

DESCRIPTION.rst is not included in the PyPi package. Using setup.py from the PyPi tarball results in the following error:

Traceback (most recent call last):
  File "setup.py", line 45, in <module>
    with io.open(path.join(here, "DESCRIPTION.rst"), encoding="utf-8") as f:
FileNotFoundError: [Errno 2] No such file or directory: '/home/brandon/Qwiic_I2C_Py/DESCRIPTION.rst'