Add a simple test for external renderer (#20033)

Fix #16402

models/fixtures/repo_unit.yml

@@ -544,3 +544,9 @@
   repo_id: 51
   type: 2
   created_unix: 946684810
+
+-
+  id: 80
+  repo_id: 53
+  type: 1
+  created_unix: 946684810

models/fixtures/repository.yml

@@ -1558,3 +1558,30 @@
   size: 0
   is_fsck_enabled: true
   close_issues_via_commit_in_any_branch: false
+
+-
+  id: 53
+  owner_id: 30
+  owner_name: user30
+  lower_name: renderer
+  name: renderer
+  is_archived: false
+  is_empty: false
+  is_private: false
+  num_issues: 0
+  num_closed_issues: 0
+  num_pulls: 0
+  num_closed_pulls: 0
+  num_milestones: 0
+  num_closed_milestones: 0
+  num_watches: 0
+  num_projects: 0
+  num_closed_projects: 0
+  status: 0
+  is_fork: false
+  fork_id: 0
+  is_template: false
+  template_id: 0
+  size: 0
+  is_fsck_enabled: true
+  close_issues_via_commit_in_any_branch: false

models/fixtures/user.yml

@@ -1102,7 +1102,7 @@
   num_followers: 0
   num_following: 0
   num_stars: 0
-  num_repos: 3
+  num_repos: 4
   num_teams: 0
   num_members: 0
   visibility: 0