chore: removed deprecated use of Logger.warn

[David-Klemenc]

resolves #56

Upon compiling I got an error for the jason library which is imported by the excoveralls library - bumping the excoveralls version fixed the problem.

The Logger.warning/2 function was added to Elixir in 1.11.0 and deprecated in version 1.15.0 so I bumped the project elixir version from 1.10.0 to 1.11.0.

[bryannaegele]

I had to fix the ci workflow. Can you rebase and push?

[David-Klemenc]

P.S. The updated deps should also get rid of makeup_erlang warning:

==> makeup_erlang
Compiling 3 files (.ex)
warning: Application.get_env/3 is discouraged in the module body, use Application.compile_env/3 instead
Warning:   lib/makeup/lexers/erlang_lexer.ex:250: Makeup.Lexers.ErlangLexer (module)

[bryannaegele]

To fix the Dialyzer issue, it needs to be pinned to the last 1.13 release.

jeremyjh/dialyxir#514

[David-Klemenc]

I created another PR there: jeremyjh/dialyxir#519 😄

And it was merged 🎊