Clean up unused 'use' statements

src/Composer/Command/ClearCacheCommand.php

@@ -14,12 +14,7 @@ namespace Composer\Command;
 
 use Composer\Cache;
 use Composer\Factory;
-use Composer\Installer;
-use Composer\Plugin\CommandEvent;
-use Composer\Plugin\PluginEvents;
 use Symfony\Component\Console\Input\InputInterface;
-use Symfony\Component\Console\Input\InputOption;
-use Symfony\Component\Console\Input\InputArgument;
 use Symfony\Component\Console\Output\OutputInterface;
 
 /**