Test additional subcommands in integration tests (#4855)

* Test additional subcommands

* Test rollback

* quote original variable

* Specifically set installer to work around #4858.

certbot-nginx/tests/boulder-integration.sh

@@ -6,14 +6,18 @@
 export PATH="/usr/sbin:$PATH"  # /usr/sbin/nginx
 nginx_root="$root/nginx"
 mkdir $nginx_root
-root="$nginx_root" ./certbot-nginx/tests/boulder-integration.conf.sh > $nginx_root/nginx.conf
+original=$(root="$nginx_root" ./certbot-nginx/tests/boulder-integration.conf.sh)
+nginx_conf="$nginx_root/nginx.conf"
+echo "$original" > $nginx_conf
+
 
 killall nginx || true
 nginx -c $nginx_root/nginx.conf
 
 certbot_test_nginx () {
     certbot_test \
-        --configurator nginx \
+        --authenticator nginx \
+        --installer nginx \
         --nginx-server-root $nginx_root \
         "$@"
 }
@@ -23,6 +27,9 @@ echo | openssl s_client -connect localhost:5001 \
     | openssl x509 -out $root/nginx.pem
 diff -q $root/nginx.pem $root/conf/live/nginx.wtf/cert.pem
 
+certbot_test_nginx rollback --checkpoints 9001
+diff -q <(echo "$original") $nginx_conf
+
 # note: not reached if anything above fails, hence "killall" at the
 # top
 nginx -c $nginx_root/nginx.conf -s stop