def yamline_write!
      lines = file_lines || []
      yamline_delete!(lines) unless lines.empty?
      lines.insert(@yamline_settings[:line], yamline)
      save_file(lines)
    end
def yamline_write!
      lines = file_lines || []
      yamline_delete!(lines) unless lines.empty?
      lines.insert(@yamline_settings[:line], yamline)
      save_file(lines)
    end
Writes the generated YAMLiner line to supplied file/files if there
is a same formated line it deletes and write again.
  a.yamline_set(:file => 'test.txt')
  a.yamline_write!