Import latest app updates from streamline

An updated set of source files and initialization was provided by streamline to
address issues observed during initial testing. These files have been updated in
order to generate a new set of app images.

docker/streamline-src/vendor/symfony/mailer/README.md

@@ -1,74 +0,0 @@
-Mailer Component
-================
-
-The Mailer component helps sending emails.
-
-Getting Started
----------------
-
-```
-$ composer require symfony/mailer
-```
-
-```php
-use Symfony\Component\Mailer\Transport;
-use Symfony\Component\Mailer\Mailer;
-use Symfony\Component\Mime\Email;
-
-$transport = Transport::fromDsn('smtp://localhost');
-$mailer = new Mailer($transport);
-
-$email = (new Email())
-    ->from('hello@example.com')
-    ->to('you@example.com')
-    //->cc('cc@example.com')
-    //->bcc('bcc@example.com')
-    //->replyTo('fabien@example.com')
-    //->priority(Email::PRIORITY_HIGH)
-    ->subject('Time for Symfony Mailer!')
-    ->text('Sending emails is fun again!')
-    ->html('<p>See Twig integration for better HTML integration!</p>');
-
-$mailer->send($email);
-```
-
-To enable the Twig integration of the Mailer, require `symfony/twig-bridge` and
-set up the `BodyRenderer`:
-
-```php
-use Symfony\Bridge\Twig\Mime\BodyRenderer;
-use Symfony\Bridge\Twig\Mime\TemplatedEmail;
-use Symfony\Component\EventDispatcher\EventDispatcher;
-use Symfony\Component\Mailer\EventListener\MessageListener;
-use Symfony\Component\Mailer\Mailer;
-use Symfony\Component\Mailer\Transport;
-use Twig\Environment as TwigEnvironment;
-
-$twig = new TwigEnvironment(...);
-$messageListener = new MessageListener(null, new BodyRenderer($twig));
-
-$eventDispatcher = new EventDispatcher();
-$eventDispatcher->addSubscriber($messageListener);
-
-$transport = Transport::fromDsn('smtp://localhost', $eventDispatcher);
-$mailer = new Mailer($transport, null, $eventDispatcher);
-
-$email = (new TemplatedEmail())
-    // ...
-    ->htmlTemplate('emails/signup.html.twig')
-    ->context([
-        'expiration_date' => new \DateTimeImmutable('+7 days'),
-        'username' => 'foo',
-    ])
-;
-$mailer->send($email);
-```
-
-Resources
----------
-
- * [Documentation](https://symfony.com/doc/current/mailer.html)
- * [Contributing](https://symfony.com/doc/current/contributing/index.html)
- * [Report issues](https://github.com/symfony/symfony/issues) and
-   [send Pull Requests](https://github.com/symfony/symfony/pulls)
-   in the [main Symfony repository](https://github.com/symfony/symfony)