Changed 'implements' by 'extends' because AbstractSchemaSynchronizer is a...

Changed 'implements' by 'extends' because AbstractSchemaSynchronizer is a class not an interface (and Eclipse PDT shows a warning that say that "The type SQLAzureFederationsSynchronizer must implement the inherited method processSqlSafely, processSql" but those methods are already implemented on AbstractSchemaSynchronizer).

lib/Doctrine/DBAL/Sharding/SQLAzure/SQLAzureFederationsSynchronizer.php

@@ -36,7 +36,7 @@ use Doctrine\DBAL\Sharding\SingleDatabaseSynchronizer;
  *
  * @author Benjamin Eberlei <kontakt@beberlei.de>
  */
-class SQLAzureFederationsSynchronizer implements AbstractSchemaSynchronizer
+class SQLAzureFederationsSynchronizer extends AbstractSchemaSynchronizer
 {
     const FEDERATION_TABLE_FEDERATED   = 'azure.federated';
     const FEDERATION_DISTRIBUTION_NAME = 'azure.federatedOnDistributionName';