Add a trait `MonadTrans` that is a PHP version of the [`MonadTrans` typeclass](http://hackage.haskell.org/package/transformers-0.5.4.0/docs/Control-Monad-Trans-Class.html#t:MonadTrans) in Haskell. Make any relevant types implement this trait.
Add a trait
MonadTransthat is a PHP version of theMonadTranstypeclass in Haskell. Make any relevant types implement this trait.