Fix Elixir 1.17 warning about function call without parens

[michallepicki]

In 5f45b8b I've fixed a warning about invoking a function without parentheses. It shows at run-time and looks like this:

warning: using map.field notation (without parentheses) to invoke function TableRex.Renderer.Text.default_options() is deprecated, you must add parentheses instead: remote.function()
  (table_rex 4.0.0) lib/table_rex/table.ex:267: TableRex.Table.render/2
  (table_rex 4.0.0) lib/table_rex/table.ex:280: TableRex.Table.render!/2

[djm]

LGTM.

[djm]

Thanks very much @michallepicki, will go out in next release.