Add library author

[jannisveerkamp]

It would be awesome if the library author would be included in the artifacts.json file, e.g. to create something like the headers in the video of this blog post: https://code.cash.app/gradle-dependency-license-validation

Is something like this possible?

[JakeWharton]

Note that we actually manually curate those for correctness. I'm not 100% convinced you can use the developer information from the pom without manually adjusting the information. I'm off the rest of the year, but I can take a look next year.