Code.compiler_options no longer accepts custom options, use Application.put_env instead
Lock Elixir's version equal or greater than 0.14
ExUnit.CallBacks.teardown_all/2 are deprecated in favor of on_exit/1 callbacks
Update README.md
Merge pull request #19 from jsvisa/v0.14

Adjust to Elixir 0.14 or higher version