text: const INITIAL_STATE = {
      isSignedIn: null,
      authToken: null
  }
  
  export default (state = INITIAL_STATE, action) =>{
      switch(action.type){
          case "SET_TOKEN":
              return {...state, authToken: action.payload};
          case "RESET_TOKEN":
              return {...state, authToken: null};
          default:
              return state;
      }
  }