roll support for users with "admin" role

[egregors]

Solution for #93 (#255) – the hard way.

• get user details (admin status, like “admin”, or “не сдался”) and save it for a time (to put it back when restriction time comms over)
  • update user DB model if it's necessary, required info (admin label) could be in user.meta, need to check it out
• revoke admin role: telegram.bot.Bot.promote_chat_member
• call mute_user_for_time as for a regular user
• find a way how to grand admin role back, when user comms back from the club
  • maybe I should put some sort of restore_admin_role function in the context.job_queue