finish redux example

docs/examples/todos/src/reducers/todos.js

@@ -1,22 +1,21 @@
 const todos = (state = [], action) => {
-  switch (action.type) {
-    case 'ADD_TODO':
-      return [
-        ...state,
-        {
-          id: action.id,
-          text: action.text,
-          completed: false
-        }
-      ]
-    case 'TOGGLE_TODO':
-      return state.map(todo =>
-        (todo.id === action.id)
-          ? {...todo, completed: !todo.completed}
-          : todo
-      )
-    default:
-      return state
+  if(action.type == 'ADD_TODO') {
+    return [
+      ...state,
+      {
+        id: action.id,
+        text: action.text,
+        completed: false
+      }
+    ]
+  } else if(action.type == 'TOGGLE_TODO') {
+    return state.map(todo =>
+      (todo.id === action.id)
+        ? {...todo, completed: !todo.completed}
+        : todo
+    )
+  } else {
+    return state
   }
 }