Add missing use statements

src/Composer/Repository/Vcs/HgDriver.php

@@ -17,6 +17,7 @@ use Composer\Json\JsonFile;
 use Composer\Util\ProcessExecutor;
 use Composer\Util\Filesystem;
 use Composer\IO\IOInterface;
+use Composer\Downloader\TransportException;
 
 /**
  * @author Per Bernhardt <plb@webfactory.de>

src/Composer/Util/Git.php

@@ -14,6 +14,7 @@ namespace Composer\Util;
 
 use Composer\Config;
 use Composer\IO\IOInterface;
+use Composer\Downloader\TransportException;
 
 /**
  * @author Jordi Boggiano <j.boggiano@seld.be>

src/Composer/Util/Svn.php

@@ -13,6 +13,7 @@
 namespace Composer\Util;
 
 use Composer\Config;
+use Composer\Downloader\TransportException;
 use Composer\IO\IOInterface;
 
 /**