License clarification

Hi,

The metadata says MIT:

```
[metadata]
name = pip-requirements-parser
license = MIT

# description must be on ONE line https://github.com/pypa/setuptools/issues/1390
description = pip requirements parser - a mostly correct pip requirements parsing library because it uses pip's own code.
long_description = file:README.rst
long_description_content_type = text/x-rst
url = https://github.com/nexB/pip-requirements-parser

author = The pip authors, nexB. Inc. and others
author_email = info@aboutcode.org

classifiers =
Development Status :: 5 - Production/Stable
Intended Audience :: Developers
Programming Language :: Python :: 3
Programming Language :: Python :: 3 :: Only
Topic :: Software Development
Topic :: Utilities

keywords =
utilities pip requirements parser dependencies pypi

license_files =
mit.LICENSE
AUTHORS.rst
CHANGELOG.rst
README.rst
```

but you also carry Apache-2.0 license file in the repo. Is this an error?

Thanks.