Remove unused use statements

src/Composer/Command/ConfigCommand.php

@@ -20,7 +20,6 @@ use Composer\Config;
 use Composer\Config\JsonConfigSource;
 use Composer\Factory;
 use Composer\Json\JsonFile;
-use Composer\Json\JsonManipulator;
 
 /**
  * @author Joshua Estes <Joshua.Estes@iostudio.com>

src/Composer/Config/ConfigSourceInterface.php

@@ -12,8 +12,6 @@
 
 namespace Composer\Config;
 
-use Composer\Json\JsonManipulator;
-
 /**
  * @author Jordi Boggiano <j.boggiano@seld.be>
  */