A few tips on what to check when you get "module is not available"
https://www.reddit.com/r/elixir/comments/8us5et/a_few_tips_on_what_to_check_when_you_get_module/
https://www.reddit.com/r/elixir/comments/8us5et/a_few_tips_on_what_to_check_when_you_get_module/