chore(client): Move client app to /client

client/src/redux/rootReducer.js

@@ -0,0 +1,9 @@
+import { combineReducers } from 'redux';
+
+import { reducer as app } from './';
+import { reducer as flash } from '../components/Flash/redux';
+
+export default combineReducers({
+  app,
+  flash
+});