Example Mix application where we try to use local as the default environment
and ci as the test environment.
Ideally, tasks should run in local by default (analogous to the dev environment).
mix test should run in the ci environment.
Ensure MIX_ENV is set to local by default. Because we expect that to be the
default environment. A .envrc file exists in the repository that will be
automatically loaded by direnv.
If you don't have direnv installed, please run export MIX_ENV=local in your
terminal.