Who said we don't need mocks in Swift...

Mocks.swift

class MockDataSource : TransporterDataSource {
	var startUpdatingLocationCalled = 0
	var stopUpdatingLocationCalled = 0
	
	func startUpdatingLocation() {
		startUpdatingLocationCalled++
	}
	
	func stopUpdatingLocation() {
		stopUpdatingLocationCalled++
	}
}