Added Scala.js branches to the Travis build.
Added Scala.js branches to the Travis build.

liff/shapeless,TomasMikula/shapeless,alexarchambault/shapeless,milessabin/shapeless,roberth/shapeless,Atry/shapeless,clhodapp/shapeless,lukasz-golebiewski/shapeless,khronnuz/shapeless,notxcain/shapeless,malcolmgreaves/shapeless,wheaties/shapeless,joescii/shapeless,lambdista/shapeless,tek/shapeless,fthomas/shapeless,isaka/shapeless,triggerNZ/shapeless