Allow developers to access the Department resource

[copypastedeveloper]

From @stevebrownlee on July 22, 2017 18:29

Verbs to be supported

1. GET
2. POST
3. PUT

• User should be able to GET a list, and GET a single item.
• If the query string parameter of ?_include=employees is provided, then all employees in the department(s) should be included in the response.
• If the query string parameters of ?_filter=budget&_gt=300000 is provided on a request for the list of departments, then any department whose budget is $300,000, or greater, should be in the response.

Copied from original issue: nashville-software-school#7