PSR-3 compliance for logging

[RinkAttendant6]

jsonrpc appears to be PSR compliant so I think that the error/exception logging should be PSR compliant too with the Logger Interface.

All that's necessary is to call the log method as per \Psr\Log\LoggerInterface instead of addRecord. The parameters are the same.

See https://github.com/php-fig/fig-standards/blob/master/accepted/PSR-3-logger-interface.md for more information.