Put config data under the key 'config' to fix issues #22 and #33

Put config data under the key 'config' to fix the config array not being returned properly in AwsServiceProvider::register(). Fixes issue #22 and #33.

This PR solves the issue for me, running the following library versions:

laravel/framework : 4.1.x-dev (2b092f8)
aws/aws-sdk-php : dev-master (35afdfb)
aws/aws-sdk-php-laravel : 1.1.1