utf8_encode() undefined

Error Message: `[critical] Message: Call to undefined function Onesimus\Logger\Adaptors\utf8_encode()`

File: `https://github.com/onesimus-systems/oslogger/blob/v2.3.2/src/Adaptors/ChromeLoggerAdaptor.php#L125`

PHP Version: 7.0

The function needs to be prefixed with a backslash for the global namespace. There's several other functions in the same file that need to be fixed as well.