Update documentation to say that 'service:scheduler' is also required in route/controller tests

[barryofguilder]

When running unit tests, I get this error:

Assertion Failed: Attempting to inject an unknown injection: 'service:scheduler'

The documentation says that service:router-scroll must be added to the needs: [] block for router/controller tests, but doesn't mention anything about service:scheduler.

Is service:scheduler required for all configurations as well? If so, this needs to be added to the documentation.

[barryofguilder]

Created PR #69 to fix this.