Deprecated: Method "Doctrine\DBAL\Types\Type::convertToDatabaseValue()" might add "mixed" as a native return type declaration in the future

[Radiergummi]

The following deprecation warnings are reported by PHP when using the library:

User Deprecated: Method "Doctrine\DBAL\Types\Type::convertToDatabaseValue()"
might add "mixed" as a native return type declaration in the future. Do the 
same in child class "BenTools\Doctrine\NativeEnums\Type\NativeEnum" now to 
avoid errors or add an explicit @return annotation to suppress this message.

User Deprecated: Method "Doctrine\DBAL\Types\Type::requiresSQLCommentHint()"
might add "bool" as a native return type declaration in the future. Do the
same in child class "BenTools\Doctrine\NativeEnums\Type\NativeEnum" now to
avoid errors or add an explicit @return annotation to suppress this message.

Adding the return types shouldn't cause any trouble, I suppose.

[bpolaszek]

Thanks @Radiergummi - I'll address this.