Use the shared secret registration API directly (#7774)

* Use the shared secret registration API directly

rather than invoking the synapse module to do it. It's probably
a bit simpler, if anything, and allows for synapse to be run in
a separate container (or rather, avoids the javascript having to have
a copy of synapse source & server config).

* Make registration secret required

Update commander (8 major versions!) to get requiredOption

* Wrong options object :/

test/end-to-end-tests/run.sh

@@ -32,9 +32,10 @@ handle_error() {
 trap 'handle_error' ERR
 
 ./synapse/start.sh
+reg_secret=`./synapse/getcfg.sh registration_shared_secret`
 if [ $has_custom_app -ne "1" ]; then
     ./element/start.sh
 fi
 yarn build
-node lib/start.js $@
+node lib/start.js --registration-shared-secret=$reg_secret $@
 stop_servers