Simple bunyan console logging stream

Logs bunyan message text to STDOUT. Output is directed to STDERR if a message's level ("fatal" (60), "error" (50), "warn" (40), "info" (30), "debug" (20), "trace" (10)) is greater or equals the value set by option stderrThreshold:

var bunyan = require('bunyan'); 
var consoleStream = require('bunyan-console-stream'); 
// ...

var stream_options = {
                       stderrThreshold:40 //log warning, error and fatal messages on STDERR
                     };

var logger = bunyan.createLogger({
                                  name: loggerName,
                                  streams: [
                                            {
                                                type: 'raw',
                                                stream: consoleStream.createStream(stream_options)
                                            },
                                            //...
                                        ]
                                });
// ...             			        
logger.info('Success!');   // STDOUT output: INFO: Success!         			        
logger.error('Fail.');     // STDERR output: ERROR: Fail.