[DBAL-722] add @since tag [ci skip]

lib/Doctrine/DBAL/Exception/DuplicateKeyException.php

@@ -23,6 +23,8 @@ use Doctrine\DBAL\DBALException;
 
 /**
  * Thrown when {@link DBALException::ERROR_DUPLICATE_KEY} is detected in driver
+ *
+ * @since 2.5
  */
 class DuplicateKeyException extends DBALException
 {

lib/Doctrine/DBAL/Exception/ForeignKeyConstraintViolationException.php

@@ -23,6 +23,8 @@ use Doctrine\DBAL\DBALException;
 
 /**
  * Thrown when {@link DBALException::ERROR_FOREIGN_KEY_CONSTRAINT} is detected in driver
+ *
+ * @since 2.5
  */
 class ForeignKeyConstraintViolationException extends DBALException
 {

lib/Doctrine/DBAL/Exception/NotNullableException.php

@@ -23,6 +23,8 @@ use Doctrine\DBAL\DBALException;
 
 /**
  * Thrown when {@link DBALException::ERROR_NOT_NULL} is detected in driver
+ *
+ * @since 2.5
  */
 class NotNullableException extends DBALException
 {