Removing universal flag from binary dist configuration

[hiranya911]

As per https://packaging.python.org/guides/distributing-packages-using-setuptools/#universal-wheels universal flag should only be used if the code works on both Python 2 and 3 without changes.

Only use the --universal setting, if:

1. Your project runs on Python 2 and 3 with no changes (i.e. it does not require 2to3).
2. Your project does not have any C extensions.

Removing the flag to only build for Python 3 from here on.

[lahirumaramba]

LGTM! Thanks!