Licence metadata is missing from pyproject.toml

[resparis]

Could you please add licences? Im trying to add to my company repository and I cant becuase the license are missing

[dmfigol]

@resparis Nornir is licensed under Apache 2.0: https://github.com/nornir-automation/nornir/blob/develop/LICENSE

[ktbyers]

Some tools use metadata submitted to pypi to validate license. Nornir is missing this metadata.

Example here:

https://github.com/python-poetry/poetry/blob/master/pyproject.toml#L8

I will update/fix this.

[ktbyers]

Also should add the following to classifiers:

        "License :: OSI Approved :: Apache Software License",