Remove setup.cfg since Python 2 is not supported

[codyscott-wbd]

Description

Drop un-needed code.

Related Issue

#492

Motivation and Context

Simplify installs and reduces cognitive load when looking at setup files.

How Has This Been Tested?

Testing by installing package.

Screenshots (if appropriate):

Types of changes

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to change)

Checklist:

• My code follows the code style of this project.
• My change requires a change to the documentation.
• I have updated the documentation accordingly.
• I have read the CONTRIBUTING document.
• I have added tests to cover my changes.
• All new and existing tests passed.