[lec06] Add tests

src/test/scala/typeclasses/FunctorSpec.scala

+package typeclasses
+
+import org.scalatest._
+import testutil.PendingIfUnimplemented
+
+@SuppressWarnings(Array("org.wartremover.warts.All"))
+class FunctorSpec extends FlatSpec with Matchers with AppendedClues with PendingIfUnimplemented {
+  "The Functor instance for Option" should "be available in implicit scope" in {
+    "implicitly[Functor[Option]]" should compile
+  }
+}

src/test/scala/typeclasses/ShowSpec.scala

+package typeclasses
+
+import org.scalatest._
+import testutil.PendingIfUnimplemented
+
+@SuppressWarnings(Array("org.wartremover.warts.All"))
+class ShowSpec extends FlatSpec with Matchers with AppendedClues with PendingIfUnimplemented {
+  "The Show instance for Person" should "be available in implicit scope" in {
+    "implicitly[Show[Person]]" should compile
+  }
+
+  it should "display in format\"[firstName] [lastName] is [age] years old\"" in {
+    // uncomment as soon as you pass the above test
+    //implicitly[Show[Person]].show(People.odersky) shouldBe "Martin Odersky is 60 years old"
+  }
+}