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/Version20161118134328.php

@@ -0,0 +1,33 @@
+<?php
+
+namespace DoctrineMigrations;
+
+use App\Doctrine\WallabagMigration;
+use Doctrine\DBAL\Schema\Schema;
+
+/**
+ * Add http_status in `entry_table`.
+ */
+class Version20161118134328 extends WallabagMigration
+{
+    public function up(Schema $schema): void
+    {
+        $entryTable = $schema->getTable($this->getTable('entry'));
+
+        $this->skipIf($entryTable->hasColumn('http_status'), 'It seems that you already played this migration.');
+
+        $entryTable->addColumn('http_status', 'string', [
+            'length' => 3,
+            'notnull' => false,
+        ]);
+    }
+
+    public function down(Schema $schema): void
+    {
+        $entryTable = $schema->getTable($this->getTable('entry'));
+
+        $this->skipIf(!$entryTable->hasColumn('http_status'), 'It seems that you already played this migration.');
+
+        $entryTable->dropColumn('http_status');
+    }
+}