How to add environment variables with flags?

[marc4gov]

Hi Bill,

Great fan of your elm contributions, I use your quickstart boilerplate and the form validation module. I would like to use environment variables, as described in (https://robots.thoughtbot.com/configuring-an-elm-app-with-environment-variables-via-webpack) However, I'd like to stay away from webpack (stuff I don't get that well...). How can I do this with your quickstart setup?

Thanks, Marc