Fix missing getter for private field test for PropertyAccess 2.3+

See: https://github.com/symfony/PropertyAccess/commit/df67239b02a9cef12cf84579f6cf569680298238
Merge pull request #338 from FriendsOfSymfony/2.0.x-property-access

Fix missing getter for private field test for PropertyAccess 2.3+
Merge branch '2.0.x' into 2.1.x

Conflicts:
	Tests/Transformer/ModelToElasticaAutoTransformerTest.php