Imported services without compiled container

[mabar]

Version: 3.0.0

In some very simple tests we create container directly instead of a compiled container

		$logger = new Logger('foo');
		$container = new Container();
		$container->addService('foo', $logger);

this causes error Nette\DI\Container::addService() service 'foo' should be defined as 'imported', but it is not possible without compilation of container.

Imho error should be triggered only if container is compiled (self::class !== static::class?)