Is there an issue with Elixir 1.5.x

[arnomi]

mix.exs specifically excludes Elixir 1.5 and higher. Is there any particular incompatibility that you know of?

[MSch]

No, we just never tested or updated it and went with the conservative choice, in anticipation that the Logger would change a lot more in newer version. If it works for you please send a PR removing the upper limit and I'll do a release if CI is green.