Remove phinx

Doctrine handle quite correctly database migration. Thanks to `doctrine:schema:update`

migrations/20150119171459_init_database.php

@@ -1,22 +0,0 @@
-<?php
-
-use Phinx\Migration\AbstractMigration;
-
-class InitDatabase extends AbstractMigration
-{
-    /**
-     * Migrate Up.
-     */
-    public function up()
-    {
-        $this->execute("INSERT INTO config (name, value) VALUES ('foo', 'bar');");
-    }
-
-    /**
-     * Migrate Down.
-     */
-    public function down()
-    {
-        $this->execute("DELETE FROM config WHERE name = 'foo' AND value = 'bar';");
-    }
-}