PHP 5.6 compat

Author: swissspidy

utils/generate-coverage.php

@@ -15,7 +15,7 @@
 $package_folder = realpath( dirname( __DIR__ ) );
 
 // If installed as a dependency in `<somedir>/vendor/wp-cli/wp-cli-tests, this is <somedir>.
-$root_folder = realpath( dirname( __DIR__, 4 ) );
+$root_folder = realpath( dirname( dirname( dirname( dirname( __DIR__ ) ) ) ) );
 
 if ( file_exists( $package_folder . '/vendor/autoload.php' ) ) {
 	$root_folder = $package_folder;