Add initial test cases

[kvvzr]

Added first tests using TestStore.

Ref: #28

[d-date]

Thank you for your contribution! And I ask you to fix some points:

• Why you back to KeyPath style: @DependencyClient will generate testValue().
• Dummy data should be under your tests if you use only for testing.

[kvvzr]

I have fixed the pointed out issues.

One point of concern is that I named it 'mock' based on the sample code from TCA, but thinking about it, 'dummy' might be a better choice. What do you think?

[d-date]

This is also macro's roll

[d-date]

Might be better with creating struct.

Suggested change

	case fetchResponse(Result<(Conference, Conference, Conference), Error>)
	case fetchResponse(Result<SchedulesResponse, Error>)

The struct may be like below:

public struct SchedulesResponse: Equatable {
  var day1: Conference
  var day2: Conference
  var workshop: Conference
}

[d-date]

One point of concern is that I named it 'mock' based on the sample code from TCA, but thinking about it, 'dummy' might be a better choice. What do you think?

Either is OK in this test.

[d-date]

Thank you for adding test! Now we're time to run it on CI!

[kvvzr]

Thank you for your review!