Add nixos test check for Wagtail admin login page

Author: jhh

.gitignore

@@ -195,3 +195,4 @@ strykeforce.sql.gz
 /static
 /cache
 /image_renditions
+.nixos-test-history

lib/overrides-strykeforce.nix

@@ -57,6 +57,7 @@ final: prev: {
 
                   strykeforce.services.website = {
                     enable = true;
+                    allowedHosts = "localhost";
                     ssl = false;
                     secrets = [ secrets ];
                   };
@@ -82,6 +83,9 @@ final: prev: {
                   # wait for service
                   machine.wait_for_unit("strykeforce-website.service")
                   machine.wait_until_succeeds("curl -sLf http://localhost:8000/static/2767/main.css")
+                  machine.succeed("curl -sLf http://localhost:8000/static/2767/main.js")
+                  html = machine.succeed("curl -sLf http://localhost:8000/admin/")
+                  assert "<title>Sign in - Wagtail</title>" in html
                 '';
             };
         };