Use an action with an actual type to get the initialSate (#115)

* Use an action with an actual type to get the initialSate

Fxes #114

* Fix code style

* Fix immutableMultireducer as well

* Code style fix

Author: yched

src/immutableMultireducer.js

@@ -11,9 +11,10 @@ export default function plainMultireducer(reducers, reducerKey) {
     }
   }
 
+  const initAction = { type: '@@multireducer/INIT' };
   const initialState = isCustomMountPoint ?
-    reducers(undefined, {}) :
-    new Immutable.Map(reducers).map(reducer => reducer(undefined, {}));
+    reducers(undefined, initAction) :
+    new Immutable.Map(reducers).map(reducer => reducer(undefined, initAction));
 
   return (state = initialState, action) => {
     if (action && action.meta && action.meta[key]) {

src/plainMultireducer.js

@@ -11,9 +11,10 @@ export default function plainMultireducer(reducers, reducerKey) {
     }
   }
 
+  const initAction = { type: '@@multireducer/INIT' };
   const initialState = isCustomMountPoint ?
-    reducers(undefined, {}) :
-    mapValues(reducers, reducer => reducer(undefined, {}));
+    reducers(undefined, initAction) :
+    mapValues(reducers, reducer => reducer(undefined, initAction));
 
   return (state = initialState, action) => {
     if (action && action.meta && action.meta[key]) {