Clean out files that should not be pushed to git for composer publish

vendor/nikic/php-parser/lib/PhpParser/ErrorHandler.php

@@ -1,13 +0,0 @@
-<?php declare(strict_types=1);
-
-namespace PhpParser;
-
-interface ErrorHandler
-{
-    /**
-     * Handle an error generated during lexing, parsing or some other operation.
-     *
-     * @param Error $error The error that needs to be handled
-     */
-    public function handleError(Error $error);
-}