Use statement for RuntimeException required in class ContainerTrait

[Henrik Maier]

A use statement needs to be added to class ContainerTrait for the RuntimeException like shown below:

<?php

namespace Psr7Middlewares\Utils;

use Interop\Container\ContainerInterface;
use InvalidArgumentException;
use RuntimeException;

otherwise the RunTimeException class will not be found when thrown as it is looked up in local namespace.

[Óscar Otero]

Good catch! Fixed in the new version.
thank you