message: Remove useless return on Logger.addLogFileStream
diff: @@ -273,7 +273,7 @@ export class Logger {
  * @param {LoggerLevelValue} [defaultLevel] The default level of the stream.
  */
  public addStream(stream: LoggerStream, defaultLevel?: LoggerLevelValue): void {
  - return this.bunyan.addStream(stream, defaultLevel);
  + this.bunyan.addStream(stream, defaultLevel);
  }
  /**
  @@ -305,8 +305,6 @@ export class Logger {
  // https://github.com/trentm/node-bunyan#stream-type-rotating-file
  this.addStream({ type: 'file', path: logFile, level: this.bunyan.level() as number });
  }
  -
  - return Promise.resolve();
  }
  /**
  