upgrade to laravel 7 and set branch to v2

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

@@ -1,25 +0,0 @@
-<?php declare(strict_types=1);
-
-namespace PhpParser;
-
-/**
- * @codeCoverageIgnore
- */
-class NodeVisitorAbstract implements NodeVisitor
-{
-    public function beforeTraverse(array $nodes) {
-        return null;
-    }
-
-    public function enterNode(Node $node) {
-        return null;
-    }
-
-    public function leaveNode(Node $node) {
-        return null;
-    }
-
-    public function afterTraverse(array $nodes) {
-        return null;
-    }
-}