5. Using ngrx in feature modules

Below you have a check list to follow.
A detailed [step by step description](https://github.com/BioPhoton/angular-ngrx-refactoring/wiki/Handling-router-state-with-%40ngrx-router-store) on how to solve the exercise is in the [wiki](https://github.com/BioPhoton/angular-ngrx-refactoring/wiki/Angular-@NGRX-Refactoring---Overview).
- [ ] Create a new folder `state-management` under `pages/flight`
- [ ] remove `flightReducer` form `app.module.ts`
- [ ] Move `ngrx/flight.actions.ts` and `ngrx/flight.reducer.ts` to the newly created folder `state-management`
- [ ] Register `flightReducer` in `pages/flight/state-management` by using the `StoreModule.forFeature` method
- [ ] Adopt imports
- [ ] Register `flightEffects` in `pages/flight/state-management` by using the `EffectsModule.forFeature` method
- [ ] Adopt imports
- [ ] Refactor the `ngrx` folder. Create `.module` for global state management file and move `IDB` interface into separate file.