Move to Symfony Flex

The structure changed completely.
Bundles are gone. Everything is flatten in the folder `src`.
I separated import & api controllers to avoid _pollution_ in the main controller folder.

migrations/Version20161128084725.php

@@ -0,0 +1,26 @@
+<?php
+
+namespace DoctrineMigrations;
+
+use App\Doctrine\WallabagMigration;
+use Doctrine\DBAL\Schema\Schema;
+
+/**
+ * Added list_mode in user config.
+ */
+class Version20161128084725 extends WallabagMigration
+{
+    public function up(Schema $schema): void
+    {
+        $configTable = $schema->getTable($this->getTable('config'));
+        $this->skipIf($configTable->hasColumn('list_mode'), 'It seems that you already played this migration.');
+
+        $configTable->addColumn('list_mode', 'integer', ['notnull' => false]);
+    }
+
+    public function down(Schema $schema): void
+    {
+        $configTable = $schema->getTable($this->getTable('config'));
+        $configTable->dropColumn('list_mode');
+    }
+}