DoctrineMigrations\Version20161014100031::dropIndex PHP Method

    protected function dropIndex(Schema $schema, $tableName, $indexName)
    {
        if (!$schema->hasTable($tableName)) {
            return false;
        }
        $table = $schema->getTable($tableName);
        if ($table->hasIndex($indexName)) {
            $table->dropIndex($indexName);
            return true;
        }
        return false;
    }