Delete app icons

Summary: Unused at this point

Test Plan: Grep

Reviewers: epriestley

Reviewed By: epriestley

Subscribers: hach-que, Korvin, epriestley

Differential Revision: https://secure.phabricator.com/D11506

scripts/celerity/generate_sprites.php

@@ -28,7 +28,6 @@ $generator = new CeleritySpriteGenerator();
 
 $sheets = array(
   'menu' => $generator->buildMenuSheet(),
-  'apps-large' => $generator->buildAppsLargeSheet(),
   'tokens' => $generator->buildTokenSheet(),
   'gradient' => $generator->buildGradientSheet(),
   'main-header' => $generator->buildMainHeaderSheet(),