add theme to login

src/app/services/theme.service.spec.ts

@@ -0,0 +1,16 @@
+import { TestBed } from '@angular/core/testing';
+
+import { ThemeService } from './theme.service';
+
+describe('ThemeService', () => {
+  let service: ThemeService;
+
+  beforeEach(() => {
+    TestBed.configureTestingModule({});
+    service = TestBed.inject(ThemeService);
+  });
+
+  it('should be created', () => {
+    expect(service).toBeTruthy();
+  });
+});

src/app/services/theme.service.ts

@@ -0,0 +1,17 @@
+import { Injectable } from '@angular/core';
+
+@Injectable({
+  providedIn: 'root'
+})
+export class ThemeService {
+
+  themes = [
+    'gov',
+    'default'
+  ]
+
+  constructor() { }
+
+  setTheme() {}
+
+}