[DDC-1317] @column(unique=true) is not semantically equivalent to @UniqueConstraint and yields invalid SQL for table create statements

output.txt

$ opensky/console doctrine:schema:update --force
Updating database schema...
string(186) "CREATE TABLE Parameter (id INT AUTO_INCREMENT NOT NULL, key VARCHAR(255) NOT NULL, value VARCHAR(255) NOT NULL, UNIQUE INDEX UNIQ_A86613B38A90ABA9 (key), PRIMARY KEY(id)) ENGINE = InnoDB"
string(2333) "#0 /home/jmikola/workspace/opensky/vendor/doctrine-dbal/lib/Doctrine/DBAL/Connection.php(618): PDO->query('CREATE TABLE Pa...')
#1 /home/jmikola/workspace/opensky/vendor/doctrine/lib/Doctrine/ORM/Tools/SchemaTool.php(641): Doctrine\DBAL\Connection->executeQuery('CREATE TABLE Pa...')
#2 /home/jmikola/workspace/opensky/vendor/doctrine/lib/Doctrine/ORM/Tools/Console/Command/SchemaTool/UpdateCommand.php(86): Doctrine\ORM\Tools\SchemaTool->updateSchema(Array, true)
#3 /home/jmikola/workspace/opensky/vendor/doctrine/lib/Doctrine/ORM/Tools/Console/Command/SchemaTool/AbstractCommand.php(59): Doctrine\ORM\Tools\Console\Command\SchemaTool\UpdateCommand->executeSchemaCommand(Object(Symfony\Component\Console\Input\ArgvInput), Object(Symfony\Component\Console\Output\ConsoleOutput), Object(Doctrine\ORM\Tools\SchemaTool), Array)
#4 /home/jmikola/workspace/opensky/vendor/symfony/src/Symfony/Bundle/DoctrineBundle/Command/Proxy/UpdateSchemaDoctrineCommand.php(63): Doctrine\ORM\Tools\Console\Command\SchemaTool\AbstractCommand->execute(Object(Symfony\Component\Console\Input\ArgvInput), Object(Symfony\Component\Console\Output\ConsoleOutput))
#5 /home/jmikola/workspace/opensky/vendor/symfony/src/Symfony/Component/Console/Command/Command.php(187): Symfony\Bundle\DoctrineBundle\Command\Proxy\UpdateSchemaDoctrineCommand->execute(Object(Symfony\Component\Console\Input\ArgvInput), Object(Symfony\Component\Console\Output\ConsoleOutput))
#6 /home/jmikola/workspace/opensky/vendor/symfony/src/Symfony/Component/Console/Application.php(191): Symfony\Component\Console\Command\Command->run(Object(Symfony\Component\Console\Input\ArgvInput), Object(Symfony\Component\Console\Output\ConsoleOutput))
#7 /home/jmikola/workspace/opensky/vendor/symfony/src/Symfony/Bundle/FrameworkBundle/Console/Application.php(75): Symfony\Component\Console\Application->doRun(Object(Symfony\Component\Console\Input\ArgvInput), Object(Symfony\Component\Console\Output\ConsoleOutput))
#8 /home/jmikola/workspace/opensky/vendor/symfony/src/Symfony/Component/Console/Application.php(117): Symfony\Bundle\FrameworkBundle\Console\Application->doRun(Object(Symfony\Component\Console\Input\ArgvInput), Object(Symfony\Component\Console\Output\ConsoleOutput))
#9 /home/jmikola/workspace/opensky/opensky/console(16): Symfony\Component\Console\Application->run()
#10 {main}"

Parameter.php

<?php

use Doctrine\ORM\Mapping as ORM;

/** @ORM\Entity */
class Parameter
{
    /**
     * @ORM\Id
     * @ORM\Column(type="integer")
     * @ORM\GeneratedValue
     */
    protected $id;

    /**
     * @ORM\Column(type="string", unique=true)
     */
    protected $key;

    /** @ORM\Column(type="string") */
    protected $value;
}