Add ripper DSL

[kddnewton]

Motivation

This doesn't quite fit in to the normal idea of a DSL, but I think it fits best here. Basically, because ripper isn't a normal gem and doesn't have a version, there's not a great way to generate static RBIs for it, because it depends on your current version of Ruby.

If this doesn't belong here and can go elsewhere, let me know.

Implementation

Loop over the defined constants at runtime, generate the definitions.

Tests

I included tests.