Code: Add install_requires to package

This package depends on other packages such as _requests_. In the current state, the user is required to install these dependencies. In order to ensure that this happens at installation step, add a _setup.cfg_ file and add the _install_requires_ in that file. Read the helpful information [here](https://godatadriven.com/blog/a-practical-guide-to-setuptools-and-pyproject-toml/).