Allow initializing a CBMServiceMock with arrays of services and characteristics

[jaylyerly]

This is a small patch to add another init method to CBMServiceMock. The existing method takes variadic parameters. Unfortunately, as far as I can tell, Swift doesn't provide a way to pass an array to a method that takes variadic params. The new init method takes arrays instead so between the two, now you can use variadic params or pass an array.

The existing init now calls the new init, so it should be getting exercised in all the unit tests.

[CLAassistant]

All committers have signed the CLA.