Openshift Cartridge Error 503


I’m trying to install Dreamfactory on my Openshift v2 account .
The installation is successful but when I try to access the application I get an internal server error,
the app log is as follows:

PHP Parse error: syntax error, unexpected ‘.’, expecting ‘&’ or variable (T_VARIABLE) in /var/lib/openshift/58c72fc889f5cfce11000016/app-root/runtime/repo/df/vendor/laravel/framework/src/Illuminate/Foundation/helpers.php on line 477

I think that this is due the PHP version.Can someone help me?