change direction right S --> W

src/main/c/labyrinth.c

@@ -13,5 +13,8 @@ void turn_direction_right(Direction *direction){
         case E:
             *direction = S;
             break;
+        case S:
+            *direction = W;
+            break;
     }
 }

src/test/c/test_labyrinth.c

@@ -37,3 +37,17 @@ void test_turn_direction_right_from_E_expected_S(void)
     /* assert */
 	TEST_ASSERT_TRUE(expected == actual);
 }
+
+void test_turn_direction_right_from_S_expected_W(void)
+{
+    /* arrange */
+    Direction actual = S;
+    Direction expected = W;
+
+    /* act */
+    turn_direction_right(&actual);
+
+    /* assert */
+	TEST_ASSERT_TRUE(expected == actual);
+}
+