skinny 1.3.4

 Skinny is a full-stack web app framework built on Scalatra.
 http://skinny-framework.org/
 Fix http://bot.brew.sh/job/Homebrew%20Pull%20Requests/16211/
 Review: inline the version into the URL https://github.com/Homebrew/homebrew/pull/33309/files#r19055353