Create items

@iedidiah 
added ability to create items.
only tested adding one item

regarding our routes: I removed the __list namespace__ which was messing us up. However, this doesn't mean items is no longer nested in lists. I think we were getting confused with the difference between a namespace and a the concept of nesting.

I might create another branch just to experiment with doing the namespace as we had it by using `Api::Lists::ItemsController`