title: How to change Last theme Applied with the initial theme in the app
body: <p>I have a custom theme in my app. it is working fine. when I changing the theme it's applied on the whole app but when restarting the app, it goes for Initially theme or default theme. 
  my question is when changing the custom theme can it be set for as the Initial theme? 
  after restarting the app, the app should go for the last applied custom theme, not the Initial theme.</p>
  
  <p><code>action function</code></p>
  
  <pre><code>    export const switchTheme = (BaseTheme) =&gt; {
       return (dispatch) =&gt; {
        dispatch({
          type      : 'SWITCH_THEME',
          baseTheme : BaseTheme
      });
     };
  };
  
   export const switchLang = (BaseLang) =&gt; {
  return (dispatch) =&gt; {
      dispatch({
          type     : 'SWITCH_LANGUAGE',
          baseLang : BaseLang
      });
    };
  };
  </code></pre>
  
  <p><code>Reducer function</code></p>
  
  <pre><code> export const initialState = {
    theme    : { ...Faded_Jade },
    language : en
  };
  
  export default function(state = initialState, action) {
    switch (action.type) {
      case 'SWITCH_THEME':
          let newState = {
              ...state,
              theme : { ...state.theme, ...action.baseTheme }
          };
          return newState;
      case 'SWITCH_LANGUAGE':
          let newlangState = {
              ...state,
              language : { ...state.language, ...action.baseLang }
          };
          return newlangState;
      default:
          return state;
    }
  }
  </code></pre>