Implement proper update process

If the version in the settings table mismatches the code version, then we return a 503 error for all requests coming through index.php and api.php, while admin.php serves up a form prompting for the database password which will run outstanding migrations.

src/Update/Console/MigrateCommand.php

@@ -0,0 +1,93 @@
+<?php
+/*
+ * This file is part of Flarum.
+ *
+ * (c) Toby Zerner <toby.zerner@gmail.com>
+ *
+ * For the full copyright and license information, please view the LICENSE
+ * file that was distributed with this source code.
+ */
+
+namespace Flarum\Update\Console;
+
+use Flarum\Console\Command\AbstractCommand;
+use Illuminate\Contracts\Container\Container;
+use Symfony\Component\Console\Input\InputInterface;
+use Symfony\Component\Console\Input\InputOption;
+use Symfony\Component\Console\Input\InputArgument;
+use Symfony\Component\Console\Output\OutputInterface;
+
+class MigrateCommand extends AbstractCommand
+{
+    /**
+     * @var Container
+     */
+    protected $container;
+
+    /**
+     * @param Container $container
+     */
+    public function __construct(Container $container)
+    {
+        $this->container = $container;
+
+        parent::__construct();
+    }
+
+    /**
+     * {@inheritdoc}
+     */
+    protected function configure()
+    {
+        $this
+            ->setName('migrate')
+            ->setDescription("Run outstanding migrations.");
+    }
+
+    /**
+     * {@inheritdoc}
+     */
+    protected function fire()
+    {
+        $this->info('Migrating Flarum...');
+
+        $this->upgrade();
+
+        $this->info('DONE.');
+    }
+
+    public function upgrade()
+    {
+        $this->container->bind('Illuminate\Database\Schema\Builder', function ($container) {
+            return $container->make('Illuminate\Database\ConnectionInterface')->getSchemaBuilder();
+        });
+
+        $migrator = $this->container->make('Flarum\Database\Migrator');
+
+        $migrator->run(base_path('core/migrations'));
+
+        foreach ($migrator->getNotes() as $note) {
+            $this->info($note);
+        }
+
+        $extensions = $this->container->make('Flarum\Extension\ExtensionManager');
+
+        $migrator = $extensions->getMigrator();
+
+        foreach ($extensions->getInfo() as $name => $extension) {
+            if (! $extensions->isEnabled($name)) {
+                continue;
+            }
+
+            $this->info('Migrating extension: '.$name);
+
+            $extensions->migrate($name);
+
+            foreach ($migrator->getNotes() as $note) {
+                $this->info($note);
+            }
+        }
+
+        $this->container->make('Flarum\Settings\SettingsRepositoryInterface')->set('version', $this->container->version());
+    }
+}