Add acceptance tests

Basic Framework for working with Selenium with PHPUnit and Firefox.
Future acceptance tests just need to extend Base.php and implement
various flows that we wish to test.

tests/acceptance/UserAuthenticationTest.php

@@ -0,0 +1,86 @@
+<?php
+
+require_once __DIR__.'/Base.php';
+
+class UserAuthenticationTest extends Base
+{
+
+    public function validLoginInputsProvider()
+    {
+        $inputs[] = [
+            [
+                'username' => 'admin',
+                'password' => 'admin',
+            ]
+        ];
+
+        return $inputs;
+    }
+
+    public function invalidLoginInputsProvider()
+    {
+        $inputs[] = [
+            [
+                'username' => 'wrong_username',
+                'password' => 'wrong_password',
+            ]
+        ];
+
+        return $inputs;
+    }
+
+    /**
+     * @dataProvider validLoginInputsProvider
+     */
+    public function testValidLogin(array $inputs)
+    {
+        $this->url('/');
+        $this->assertContains('Login', $this->title());
+
+        $form = $this->byTag('form');
+        foreach ($inputs as $input => $value) {
+            $form->byName($input)->value($value);
+        }
+        $form->submit();
+
+        $content = $this->byClassName('sidebar')->text();
+        $this->assertContains($inputs['username'], $content);
+    }
+
+    /**
+     * @dataProvider invalidLoginInputsProvider
+     */
+    public function testInvalidLogin(array $inputs)
+    {
+        $this->url('/');
+
+        // Test wrong username with correct password
+        $form = $this->byTag('form');
+        $form->byName('username')->value($inputs['username']);
+        $form->byName('password')->value('admin');
+        $form->submit();
+
+        $content = $this->byTag('body')->text();
+        $this->assertContains('Bad username or password', $content);
+
+        // Test wrong password with correct username
+        $form = $this->byTag('form');
+        $form->byName('username')->value('admin');
+        $form->byName('password')->value($inputs['password']);
+        $form->submit();
+
+        $content = $this->byTag('body')->text();
+        $this->assertContains('Bad username or password', $content);
+
+        // Test wrong username and password
+        $form = $this->byTag('form');
+        $form->byName('username')->value($inputs['username']);
+        $form->byName('password')->value($inputs['password']);
+        $form->submit();
+
+        $content = $this->byTag('body')->text();
+        $this->assertContains('Bad username or password', $content);
+
+
+    }
+}