MAPG-69 merge SignupController to LoginController and introduce Google login/sign up

views/login/google_login.php

@@ -0,0 +1,9 @@
+<?php require ROOT . '/views/templates/main_header.php'; ?>
+<?php require ROOT . '/views/templates/header.php'; ?>
+<div class="main">
+    <h2>Login up with Google</h2>
+    <div class="box">
+        <p class="error justify">Authenticating with Google failed. Please <a href="/login/google" title="Login with Google">retry</a>!</p>
+    </div>
+</div>
+<?php require ROOT . '/views/templates/main_footer.php'; ?>