Reverse dependencies for stale_fish

Latest version of the following gems require stale_fish

Gem	Version	Date	Downloads
pivotal-tracker +910 Thousand Downloads	`0.5.13` March 26, 2015	March 26, 2015	910 Thousand
pivotal-tracker-fox +13.2 Thousand Downloads	`0.5.13` August 05, 2013	August 05, 2013	13.2 Thousand
topprospect-pivotal-tracker +8.22 Thousand Downloads	`0.1.1` June 28, 2011	June 28, 2011	8.22 Thousand
tsenart-pivotal-tracker +7.98 Thousand Downloads	`0.5.0` July 08, 2011	July 08, 2011	7.98 Thousand