Upcoming breaking change in crystal 0.26.0

Created by: bcardiff

While preparing the release for 0.26 I reach that https://github.com/jwaldrip/shell-table.cr/blob/v0.9.2/src/shell-table.cr#L30 conflicts with https://github.com/crystal-lang/crystal/pull/6324

Syntax error in lib/shell-table/src/shell-table.cr:30: setter method 'labels=' cannot have more than one argument

  def labels=(*args, **props)