Reverse dependencies for slides

Latest version of the following gems require slides

Gem	Version	Date	Downloads
rack-instruments +59.1 Thousand Downloads	`0.4.0` March 07, 2014	March 07, 2014	59.1 Thousand
sequel-instruments +4.85 Thousand Downloads	`0.1.0` July 18, 2012	July 18, 2012	4.85 Thousand
excon-slides_instrumentor +4.83 Thousand Downloads	`0.1.0` September 09, 2012	September 09, 2012	4.83 Thousand