Add some simple dependency injection.

Add iInject to any class that you may need to have parameters injected
into. The web project needs a file called di.json which maps the
interface to the implementation. You can do constructor injection or
property injection by annotating your public property with /** @inject
iInterfaceName */ right above it. See the Melodic Services project for
an example. The School.php api controller injects the unit of work.