Make `init.author` prompt like `init.license`

[ljharb]

https://github.com/npm/init-package-json/blob/master/default-input.js#L182-L194 doesn't prompt if the author is specified. However, https://github.com/npm/init-package-json/blob/master/default-input.js#L196-L200 prompts regardless, and just uses the init.license value as a default.

Would it be possible to prompt the user to confirm the init.author settings as well?

[DanielFGray]

I support this. Although having different authors does seem like a rare occurrence, the option to change it should be there without having to unset init.author or manually edit the package.json file.

[kevinSuttle]

Not necessarily rare if your company has their own registry.

[wraithgar]

Added to npm/statusboard#930

[owlstronaut]

#352