Change gem doc link to rubydoc.info
Change gem doc link to rubydoc.info

Ultimately we will want to host the docs ourselves via github pages. For now, this is easier.
cocktail-io/ruby-asana,cocktail-io/ruby-asana,Asana/ruby-asana,cocktail-io/ruby-asana,Asana/ruby-asana,Asana/ruby-asana