Remove blank line, remove unused import, remove ToDo comment

src/app/authentication.guard.ts

 import { Injectable } from '@angular/core';
 import { CanActivate, ActivatedRouteSnapshot, RouterStateSnapshot, Router } from '@angular/router';
-import { Observable } from 'rxjs/Observable';
 import { AuthenticationService } from './authentication.service';
 import 'rxjs/add/operator/map';
 import 'rxjs/add/observable/of';

src/app/authentication.interceptor.ts

@@ -40,5 +40,4 @@ export class AuthenticationInterceptor implements HttpInterceptor {
       return next.handle(req);
     }
   }
-
 }

src/app/authentication.service.ts

@@ -7,7 +7,6 @@ import { DataStoreService } from './data-store.service';
 import { HttpClient, HttpHeaders } from '@angular/common/http';
 import { ClientAuthentication } from './client-authentication';
 
-// TODO: connect to API
 @Injectable()
 export class AuthenticationService {
   private readonly STORAGE_KEY: string = 'USER';