initialize Winston logging mechanism from file (Synchronous, no callback)
function fromFileSync(filename) {
  var configFile = filename || '../config/winston-config.json';

  var exists = fs.existsSync(configFile);

  if (exists) {
    var winstonConf = require(configFile).logging;

    if (_isEmpty(winstonConf)) {
      console.log('Empty winston configuration');
    } else {
      configLogger(winstonConf);
    }

  } else {
    console.log('No config file found (at least provide a config/winston-config.json) with winston configuration');
  }

  return winston;
}