Backporting fixes and/or re-lowering Elixir requirements

[whitfin]

This is in regards to #35.

I am maintainer of several projects using this project, but they're targeted (on the lower end) against Elixir versions prior to v1.11. It looks like in the mainline of this repository the requirement shifted to 1.11+ due to logging changes, and unfortunately I need the patch referenced above 😱

Would you consider accepting a patch to re-lower it with a conditionally compiled logging call?

if Version.match?(System.version(), ">= 1.11.0") do
  defp warn(msg),
    do: Logger.warning(msg)
else
  defp warn(msg),
    do: Logger.warn(msg)
end

As an aside, the current main branch does not compile due to invalid syntax in this snippet: https://github.com/bitwalker/libring/blob/main/lib/managed_ring.ex#L33-L45

That being said if this was made valid I think it would also affect the min Elixir version requirement by the use of optional() so that might have some impact on this thread.

I know people will say Elixir < v1.11 is "old", but enterprise moves at different speeds sometimes and I think it's fairly simple to stay compatible here. Thanks for your consideration!