Admins can create dive sites

https://trello.com/c/75nn9Dyi/30-as-an-admin-i-can-add-dive-sites

![image](https://cloud.githubusercontent.com/assets/8681076/5075561/e00c7362-6e61-11e4-99df-ccaf296bd753.png)

![image](https://cloud.githubusercontent.com/assets/8681076/5075480/14f962ca-6e61-11e4-81d4-9bd8f7662f3d.png)