[CJ/EC][76395676] add envs, default to config.edn

app config now requires three keys:
{:clj-config/environments #{:dev :ci :qa :production}
 :clj-config/default-key  :default
 :clj-config/app-config   {:sentry-dsn {:dev nil
                                        [:ci :qa] "ci/qa sentry dsn"...}}