Enable OTP 2FA

- Update SchebTwoFactorBundle to version 3
- Enable Google 2fa on the bundle
- Disallow ability to use both email and google as 2fa
- Update Ocramius Proxy Manager to handle typed function & attributes (from PHP 7)
- use `$this->addFlash` shortcut instead of `$this->get('session')->getFlashBag()->add`
- update admin to be able to create/reset the 2fa

tests/Wallabag/UserBundle/Mailer/AuthCodeMailerTest.php

@@ -33,7 +33,7 @@ TWIG;
     public function testSendEmail()
     {
         $user = new User();
-        $user->setTwoFactorAuthentication(true);
+        $user->setEmailTwoFactor(true);
         $user->setEmailAuthCode(666666);
         $user->setEmail('test@wallabag.io');
         $user->setName('Bob');