Add 4 first unit-tests for Routers and Interactors.

Summary:
Now that we have protocol mocks, we can instantiate RootRouter, RootInteractor, SplashRouter, SplashInteractor by providing them with "fake" (mock) dependencies, instead of actual objects.
I.e., to instantuate `RootRouter` object in a unit-test, we provide it with mock implementations of `interactor: RootInteractable`, `viewController: RootViewControllable` and `splashBuilder: SplashBuildable` objects,
so that we can test side-effects easily.

There is one unsolved problem still: base RIB's protocols aren't annotated with `/// sourcery: ` annotations, and the mock generator did not generate them for us.
These are required to be able to instantiate instances of *mock* classes, e.g., `RootRoutingMock` - it requires `interactable: Interactable` and `viewControllable: ViewControllable` objects to be passed in its initializer.
We'll handle this in the next commit.

Author: ivanmisuno

Tutorial_RIBs_CodeGenerationTests/Root/RootInteractorSpec.swift

@@ -13,13 +13,32 @@ import RIBs
 
 class RootInteractorSpec: TestSpec {
     override func spec() {
-        /*
-        var presenter: RootPresentable!
+        var presenter: RootPresentableMock!
         var sut: RootInteractor!
+        //var router: RootRoutingMock!
         beforeEach {
-            //presenter = RootPresentable
+            presenter = RootPresentableMock()
             sut = RootInteractor(presenter: presenter)
+
+//            router = RootRoutingMock(interactable: <#T##Interactable#>, viewControllable: <#T##ViewControllable#>) // TODO: same here.
+//            sut.router = router
         }
-         */
+
+        // MARK: - init()
+        describe("init()") {
+            it("sets presenter.listener to self") {
+                expect(presenter.listener) === sut
+            }
+        } // describe("init()")
+
+//        // MARK: - didBecomeActive()
+//        describe("didBecomeActive()") {
+//            beforeEach {
+//                sut.activate()
+//            }
+//            it("calls router.routeToSplash()") {
+//                expect(router.routeToSplashCallCount) == 1
+//            }
+//        } // describe("didBecomeActive()")
     }
 }

Tutorial_RIBs_CodeGenerationTests/Root/RootRouterSpec.swift

@@ -13,19 +13,35 @@ import RIBs
 
 class RootRouterSpec: TestSpec {
     override func spec() {
-        /*
-        var interactor: RootInteractable!
-        var viewController: RootViewControllable!
-        var splashBuilder: SplashBuildable!
+        var interactor: RootInteractableMock!
+        var viewController: RootViewControllableMock!
+        var splashBuilder: SplashBuildableMock!
         var sut: RootRouter!
         beforeEach {
-            //interactor = ???
-            //viewController = ???
-            //splashBuilder = ???
+            interactor = RootInteractableMock()
+            viewController = RootViewControllableMock(uiviewController: UIViewController())
+            splashBuilder = SplashBuildableMock()
             sut = RootRouter(interactor: interactor,
                              viewController: viewController,
                              splashBuilder: splashBuilder)
         }
-        */
+
+        // MARK: - init()
+        describe("init()") {
+            it("sets interactor.router to self") {
+                expect(interactor.router) === sut
+            }
+        } // describe("init()")
+
+        // MARK: - routeToSplash()
+        describe("routeToSplash()") {
+//            var splashRouter: SplashRoutingMock!
+//            beforeEach {
+//                splashBuilder.buildHandler = { (_ listener: SplashListener) -> (SplashRouting) in
+//                    splashRouter = SplashRoutingMock(interactable: <#T##Interactable#>, viewControllable: <#T##ViewControllable#>) // TODO: Oops, need mocks for base RIBs' protocols (`Interactable`, `ViewControllable`), but we can't annotate them (yet). Will solve that in the next commit.
+//                    return splashRouter
+//                }
+//            }
+        } // describe("routeToSplash()")
     }
 }

Tutorial_RIBs_CodeGenerationTests/Splash/SplashInteractorSpec.swift

@@ -13,12 +13,19 @@ import RIBs
 
 class SplashInteractorSpec: TestSpec {
     override func spec() {
-        /*
-        var presenter: SplashPresentable!
+        var presenter: SplashPresentableMock!
         var sut: SplashInteractor!
         beforeEach {
+            presenter = SplashPresentableMock()
             sut = SplashInteractor(presenter: presenter)
         }
-         */
+
+        // MARK: - init()
+        describe("init()") {
+            it("sets presenter.listener to self") {
+                expect(presenter.listener) === sut
+            }
+        } // describe("init()")
+
     }
 }

Tutorial_RIBs_CodeGenerationTests/Splash/SplashRouterSpec.swift

@@ -13,14 +13,21 @@ import RIBs
 
 class SplashRouterSpec: TestSpec {
     override func spec() {
-        /*
-        var interactor: SplashInteractable!
-        var viewController: SplashViewControllable!
+        var interactor: SplashInteractableMock!
+        var viewController: SplashViewControllableMock!
         var sut: SplashRouter!
         beforeEach {
-            sut = SplashRouter(interactor: <#T##SplashInteractable#>,
-                               viewController: <#T##SplashViewControllable#>)
+            interactor = SplashInteractableMock()
+            viewController = SplashViewControllableMock(uiviewController: UIViewController())
+            sut = SplashRouter(interactor: interactor,
+                               viewController: viewController)
         }
-         */
+
+        // MARK: - init()
+        describe("init()") {
+            it("sets interactor.router to self") {
+                expect(interactor.router) === sut
+            }
+        } // describe("init()")
     }
 }