Remove broken link (#770)

I saw that we still link to the ember guides in the main readme, but
we've since removed those guides. Here I remove the link in the readme
as well.

Author: jutonz

README.md

@@ -60,7 +60,6 @@ programming in style.
 ### Frameworks and platforms
 
 - [Android](/android/)
-- [Ember](/ember/)
 - [iOS](/ios/)
 - [Rails](/rails/)
 - [React](/react/)