Type-check tokenizer/index.js (#460)
Type-check tokenizer/index.js (#460)

* Type-check tokenizer/index.js

* Update test baselines

jridgewell/babel,hzoo/babel,babel/babel,PolymerLabs/babel,claudiopro/babel,samwgoldman/babel,shuhei/babel,babel/babylon,kellyselden/babel,existentialism/babel,lightscript/babylon-lightscript,jridgewell/babel,maurobringolf/babel,maurobringolf/babel,hulkish/babel,jridgewell/babel,guybedford/babel,samwgoldman/babel,samwgoldman/babel,babel/babel,kellyselden/babel,hzoo/babel,maurobringolf/babel,chicoxyzzy/babel,existentialism/babel,kaicataldo/babel,PolymerLabs/babel,claudiopro/babel,claudiopro/babel,chicoxyzzy/babel,hulkish/babel,kellyselden/babel,hulkish/babel,chicoxyzzy/babel,shuhei/babel,babel/babel,chicoxyzzy/babel,existentialism/babel,guybedford/babel,kellyselden/babel,hzoo/babel,babel/babel,vadzim/babel,kaicataldo/babel,vadzim/babel,PolymerLabs/babel,Skillupco/babel,hzoo/babel,Skillupco/babel,kaicataldo/babel,Skillupco/babel,cbishopvelti/babylon,kaicataldo/babel,hulkish/babel,guybedford/babel,Skillupco/babel,shuhei/babel,jridgewell/babel