Implement logout

Signed-off-by: William Brawner <me@wbrawner.com>

src/app/app.component.ts

@@ -33,7 +33,9 @@ export class AppComponent {
   }
 
   logout(): void {
-    this.twigsService.logout();
+    this.twigsService.logout().subscribe(_ => {
+      this.location.go('/');
+    });
   }
 
   isLoggedIn() {

src/app/shared/twigs.http.service.ts

@@ -43,7 +43,7 @@ export class TwigsHttpService implements TwigsService {
   }
 
   logout(): Observable<void> {
-    return Observable.throw('Not Implemented');
+    return this.http.post<void>(this.apiUrl + '/logout', this.options);
   }
 
   // Budgets