Using bs-webapi

[schutm]

HI,

just like #127 and more pull reqyuest, I find my self more and more expanding the provided types, introducing bare javascript or using the (more) complete bs-webapi package.

Would it make sense to remove all the web stuff from Bucklescript-Tea and use bs-webapi in stead? I do understand this introduces a new dependency and is bigger, but it would provide a more complete web api as well.