UPGRADE FROM 5.1 to 5.2
=======================
Mime
----
* Deprecated `Address::fromString()`, use `Address::create()` instead
Validator
---------
* Deprecated the `allowEmptyString` option of the `Length` constraint.
Before:
```php
use Symfony\Component\Validator\Constraints as Assert;
/**
* @Assert\Length(min=5, allowEmptyString=true)
*/
```
After:
* @Assert\AtLeastOneOf({
* @Assert\Blank(),
* @Assert\Length(min=5)
* })