Update apps.md - Removed unused screenshot (travis-ci#3348)

Removed screenshot for Screensaver Ninja (Mac) that looks like it was left in by mistake. App appears to have been discontinued and previously removed from this page, but screenshot was not under heading so it got missed slightly breaking the page layout.

Author: Soulflare3

user/apps.md

@@ -198,8 +198,6 @@ By ThoughtWorks Inc.
 - [app store](https://itunes.apple.com/us/app/ccmenu/id603117688)
 - [tutorial](/user/cc-menu/)
 
-![Travis CI in Screensaver Ninja with Custom CSS](/images/apps/screensaver-ninja.gif){:.app}
-
 ## Linux
 
 ### BuildNotify