Add requirements to setup.cfg

[shubhank-saxena]

This fixes #76

Description

This PR aims to clean requirements (both main and dev) and add them under setup.cfg file.

Affected Dependencies

All the installation dependencies are migrated

Checklist

• [x] I have followed the Contribution Guidelines and Code of Conduct
• [x] I have commented my code following the OpenMined Styleguide
• [ ] I have labeled this PR with the relevant Type labels
• [x] My changes are covered by tests

[shubhank-saxena]

@rasswanth-s I am not sure what's the issue with the git URL installation of syft. I followed the following doc - https://setuptools.readthedocs.io/en/latest/userguide/dependency_management.html#dependencies-that-aren-t-in-pypi

[rasswanth-s]

Sure , I will take a look at it.