Latest composer causes an issue with JsonValidator loading due to PSR-4 change

[gmoreira]

@phiamo today this issue has come up. This is how it appears:

$ php app/console mopa:bootstrap:symlink:less --force
Initializing composer ...
PHP Fatal error:  Class 'JsonSchema\Validator' not found in phar:///..blah../composer.phar/src/Composer/Json/JsonFile.php on line 160
[Symfony\Component\Debug\Exception\ClassNotFoundException]
Attempted to load class "Validator" from namespace "JsonSchema".
Did you forget a "use" statement for e.g. "Symfony\Component\Validator\Validator", "JMS\DiExtraBundle\Annotation\Validator", "JMS\DiExtraBundle\Tests\Fixture\Validator\Validator", "Gedmo\ReferenceIntegrity\Mapping\Validator", "Gedmo\SoftDeleteable\Mapping\Validator", "Gedmo\Tree\Mapping\Validator" or "Gedmo\Uploadable\Mapping\Validator"?
mopa:bootstrap:symlink:less [-f|--force] [-m|--manual] [--no-symlink] [pathToTwitterBootstrap] [pathToMopaBootstrapBundle]

In my initial look at this, It would seem that the composer bridge needs to also load the PSR-4 autoloader?

In composer this is the change that has caused this:
composer/composer@1215e19
Which was a fall on effect of this change in one of it's dependencies:
jsonrainbow/json-schema@344315f