typings-global is obsolete

[stramel]

!!!!!!!!!!!
typings-global is obsolete! Remove it!
Use `yarn add --dev @types/node` instead!
!!!!!!!!!!!

[philkunz]

@stramel I'll take care of it. I see you committed some stuff to the Polymer Modulizer. :D Much needed and anticipated :)

[stramel]

@philkunz Thank you for being on top of this! May be good in the future to update to the now stable v4 of gulp as well.

I have been adding a little bit here and there however the real heros are @FredKSchott and the rest of the polymer tools team. :)