@types/validator is a production dependency

[Llois41]

Description

@types/validator is a production dependency, but it should be a devDependency instead

I submitted a PR. Maybe a maintainer could have a look :)

[braaar]

I'm thinking there must be a reason why it's listed as a dependency. Without looking into it, I think it's possible that some of the types from there are used in the exported types from this library, meaning that the types are a part of the product, not just something we use during development. This would be different in a non-library project, where typescript types are always just used during development (they don't exist in an actually running javascript program, of course)