test: initialize e2e-testing with login page (#698)

Fixes: #697

e2e/src/login/login.e2e-spec.ts

@@ -0,0 +1,24 @@
+import { browser, by, element } from 'protractor';
+import { LoginPage } from './login.po';
+
+describe('app', () => {
+  let page: LoginPage;
+
+  beforeAll(() => {
+    page = new LoginPage();
+  });
+
+  it('should display login page', () => {
+    expect(browser.getCurrentUrl()).toContain('/login');
+  });
+
+  it('should display error with invalid credentials', () => {
+    page.invalidLogin();
+    expect(element(by.tagName('mat-error')).isPresent()).toBe(true);
+  });
+
+  it('should login into the app', () => {
+    page.validLogin();
+  });
+
+});