Remove unused imports

Author: alexandre-daubois

Tests/ProcessTest.php

@@ -16,7 +16,6 @@
 use Symfony\Component\Process\Exception\LogicException;
 use Symfony\Component\Process\Exception\ProcessFailedException;
 use Symfony\Component\Process\Exception\ProcessSignaledException;
-use Symfony\Component\Process\Exception\ProcessStartFailedException;
 use Symfony\Component\Process\Exception\ProcessTimedOutException;
 use Symfony\Component\Process\Exception\RuntimeException;
 use Symfony\Component\Process\InputStream;