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/Version20170501115751.php

@@ -0,0 +1,38 @@
+<?php
+
+namespace DoctrineMigrations;
+
+use App\Doctrine\WallabagMigration;
+use Doctrine\DBAL\Schema\Schema;
+
+/**
+ * Add site credential table to store username & password for some website (behind authentication or paywall).
+ */
+class Version20170501115751 extends WallabagMigration
+{
+    public function up(Schema $schema): void
+    {
+        $this->skipIf($schema->hasTable($this->getTable('site_credential')), 'It seems that you already played this migration.');
+
+        $table = $schema->createTable($this->getTable('site_credential'));
+        $table->addColumn('id', 'integer', ['autoincrement' => true]);
+        $table->addColumn('user_id', 'integer');
+        $table->addColumn('host', 'string', ['length' => 255]);
+        $table->addColumn('username', 'text');
+        $table->addColumn('password', 'text');
+        $table->addColumn('createdAt', 'datetime');
+        $table->addIndex(['user_id'], 'idx_user');
+        $table->setPrimaryKey(['id']);
+        $table->addForeignKeyConstraint($this->getTable('user'), ['user_id'], ['id'], [], 'fk_user');
+
+        if ('postgresql' === $this->connection->getDatabasePlatform()->getName()) {
+            $schema->dropSequence('site_credential_id_seq');
+            $schema->createSequence('site_credential_id_seq');
+        }
+    }
+
+    public function down(Schema $schema): void
+    {
+        $schema->dropTable($this->getTable('site_credential'));
+    }
+}