contribute fluent log builder

Writing info message via fluent API.

    _logger.Info()
        .Message("This is a test fluent message '{0}'.", DateTime.Now.Ticks)
        .Property("Test", "InfoWrite")
        .Write();

Writing error message.

    try
    {
        string text = File.ReadAllText(path);
    }
    catch (Exception ex)
    {
        _logger.Error()
            .Message("Error reading file '{0}'.", path)
            .Exception(ex)
            .Property("Test", "ErrorWrite")
            .Write();
    }