Reverse dependencies for slides

Latest version of the following gems require slides

Gem	Version	Date	Downloads
rack-instruments +59.7 Thousand Downloads	`0.4.0` March 07, 2014	March 07, 2014	59.7 Thousand
sequel-instruments +4.89 Thousand Downloads	`0.1.0` July 18, 2012	July 18, 2012	4.89 Thousand
excon-slides_instrumentor +4.87 Thousand Downloads	`0.1.0` September 09, 2012	September 09, 2012	4.87 Thousand