Make it possible to read updates in listening mode

[leonovk]

I had a need for the bot to read all incoming updates when it was in polling mode, not just messages. This is very useful when, for example, you need the bot to work in polling mode in one environment and via webhooks in another, without changing the code itself.

It will look like this:

  Telegram::Bot::Client.run(token, listen_update_mode: true) do |bot|
    bot.listen do |update|
      # something
    end
  end

[leonovk]

UPD also fixed the fallen linter