Remove : void for PHP version compat

Author: danielbachhuber

tests/test-arguments.php

@@ -96,7 +96,7 @@ public function setUp()
     /**
      * Tear down fixtures
      */
-    public function tearDown(): void
+    public function tearDown()
     {
         $this->flags = null;
         $this->options = null;

tests/test-table-ascii.php

@@ -37,7 +37,7 @@ public function setUp() {
 	/**
 	 * Cleans temporary file
 	 */
-	public function tearDown(): void {
+	public function tearDown() {
 		if (file_exists($this->_mockFile)) {
 			unlink($this->_mockFile);
 		}