https://hackmd.io/LQmb1PLXQWq1mzBo86VtdA?view
Set environment variables.
.envrc
export GITHUB_ID="Iv1.234567890"
export GITHUB_SECRET="secretsecretsecretsecret"
export RAILS_ENV=production
export RAILS_SERVE_STATIC_FILES=enabled
export RAILS_LOG_TO_STDOUT=enabled
See Makefile