Log Message:
Update ruby-sinatra to 1.4.6.

= 1.4.6 / 2015-03-2x

 * Improve tests and documentation. (Dar«¿o Here«Ð«â, Seiichi \ 
Yonezawa, kyoendo,
   John Voloski, Ferenc-, Renaud Martinet, Christian Haase, marocchino,
   huoxito, Damir Svrtan, Amaury Medeiros, Jeremy Evans, Kashyap, shenqihui,
   Ausmarton Fernandes, kami, Vipul A M, Lei Wu, 7stud, Taylor Shuler,
   namusyaka, burningTyger, Cornelius Bock, detomastah, hakeda, John Hope,
   Ruben Gonzalez, Andrey Deryabin, attilaolah, Anton Davydov, Nikita Penzin,
   Dyego Costa)

 * Remove duplicate require of sinatra/base. (Alexey Muranov)

 * Escape HTML in 404 error page. (Andy Brody)

 * Refactor to method call in `Stream#close` and `#callback`. (Damir Svrtan)

 * Depend on latest version of Slim. (Damir Svrtan)

 * Fix compatibility with Tilt version 2. (Yegor Timoschenko)

 * Fix compatibility issue with Rack `pretty` method from ShowExceptions.
   (Kashyap)

 * Show date in local time in exception messages. (tayler1)

 * Fix logo on error pages when using Ruby 1.8. (Jeremy Evans)

 * Upgrade test suite to Minitest version 5 and fix Ruby 2.2 compatibility.
   (Vipul A M)