Missing convert adjectives to their original form

There is no method to convert adjectives to their original form.

There are toComparative and toSuperlative methods, but toOriginal (toRoot) is not exposed:

https://github.com/spencermountain/compromise/blob/2831ad3f5393889d48ddd051f3c8f53fa758ce03/src/3-three/adjectives/plugin.js#L3-L13