Fix namespace of MappingDriverChain in example

[rieschl]

Since doctrine/persistence 1.3.0 the namespace of the package was moved from Doctrine\Common\Persistence to Doctrine\Persistence. The forward compatibility classes were removed in 2.0.0.

This fix changes the namespace to the new one, which should work in doctrine/persistence >= 1.3.0

[asgrim]

@rieschl Do we need a class alias for this to work in both older and newer dependencies?

[rieschl]

@asgrim The class-aliases were added in doctrine/peristence 1.3.0, so we shouldn't need them here. But maybe we should add a dependency for doctrine/persistence in composer.json to reflect that. Implicitly, doctrine/peristence >= 1.3.0 is required anyways because the DriverFactory uses them already.

edit: composer-require-checker tells me the same 🙂

$ vendor/bin/composer-require-checker
ComposerRequireChecker 3.3.0@4063254c611acf34f1c15b29b6bcc47d2e7a9a9e
The following 19 unknown symbols were found:
+--------------------------------------------------------+--------------------+
| Unknown Symbol                                         | Guessed Dependency |
+--------------------------------------------------------+--------------------+
| Doctrine\Common\Annotations\AnnotationReader           |                    |
| Doctrine\Common\Annotations\AnnotationRegistry         |                    |
| Doctrine\Common\Annotations\CachedReader               |                    |
| Doctrine\Common\Cache\ApcuCache                        |                    |
| Doctrine\Common\Cache\ArrayCache                       |                    |
| Doctrine\Common\Cache\CacheProvider                    |                    |
| Doctrine\Common\Cache\ChainCache                       |                    |
| Doctrine\Common\Cache\FilesystemCache                  |                    |
| Doctrine\Common\Cache\MemcachedCache                   |                    |
| Doctrine\Common\Cache\PhpFileCache                     |                    |
| Doctrine\Common\Cache\PredisCache                      |                    |
| Doctrine\Common\Cache\RedisCache                       |                    |
| Doctrine\Common\Cache\WinCacheCache                    |                    |
| Doctrine\Common\Cache\ZendDataCache                    |                    |
| Doctrine\Common\EventManager                           |                    |
| Doctrine\Common\EventSubscriber                        |                    |
| Doctrine\Persistence\Mapping\Driver\AnnotationDriver   |                    |
| Doctrine\Persistence\Mapping\Driver\FileDriver         |                    |
| Doctrine\Persistence\Mapping\Driver\MappingDriverChain |                    |
+--------------------------------------------------------+--------------------+

[asgrim]

@rieschl yeah OK, I'm a fan of adding the dependency (given we had a similar issue in #46 too because of implicit dependencies), so lets do that please and this is good to go I think :+1:

[rieschl]

alright. I should rebase the PR to 3.1.x, right?

[asgrim]

alright. I should rebase the PR to 3.1.x, right?

ah, yes please :)

[asgrim]

Thanks @rieschl !