Add authors to required fields

[abitrolly]

Relates-to: python-poetry/poetry#407
Relates-to: python-poetry/poetry#3155

• Added tests for changed code.

• Updated documentation for changed code.

  The documentation was fixed in Added required to authors field in the documentation. poetry#412

UPDATE: I see this is a duplicate of #37 Let me add tests to it.

[abitrolly]

Unable to run tests, because poetry install fails. Looking into this.

$ poetry install
The lock file might not be compatible with the current version of Poetry.
Upgrade Poetry to ensure the lock file is read properly or, alternatively, regenerate the lock file with the `poetry lock` command.
Installing dependencies from lock file

[RecursionError]
maximum recursion depth exceeded while calling a Python object

[abitrolly]

@python-poetry/triage this is ready for review.

[abitrolly]

This is hacktoberfest related PR. Any chance to get it merged before the deadline? Pretty please. :D

[luni3359]

While this is now in the documentation, poetry check still incorrectly marks the pyproject.toml file as correct even if the authors key is missing.

[abitrolly]

The indentation in 44167a5 made this PR unmergeable. I am looking for a way to fix this.

[abitrolly]

Rebased and ready for review again.

[Secrus]

Superseeded by #437

[abitrolly]

Stealing PRs is unfair! :D