Add support for peek, touch, release

[frommww]

Add support in the gem for peek, touch, and release.

http://dev.iron.io/mq/reference/api/#peek_messages_on_a_queue http://dev.iron.io/mq/reference/api/#touch_a_message_on_a_queue http://dev.iron.io/mq/reference/api/#release_a_message_on_a_queue

[featalion]

hey @treeder, I have suggestions on the gem:

• Get rid of Queues and Messages classes. They seems superfluous. Queue, Message and Client classes have all needed to create API calls, so we'll needs only store #path methods.
• Client supports "default" queue, but it not API reflection as I understood. Is the gem must support "default" queue? As we provide client.queue("with_name") syntax for getting a queue this feature seems odd.
• Support Hashie 3rdparty as IronWorker gem does. To indifferent access. I discussed on it with @iced . He suggested to embed Hashie to IronCore.

What do you think?

[featalion]

@frommww @treeder done at https://github.com/featalion/iron_mq_ruby/tree/new_design + documentation

[featalion]

it also adds feature which is not documented on dev.iron.io

DELETE /projects/{Project ID}/queues/{Queue Name}/messages/{Message ID}/subscribers/{Subscriber ID}