Move installed data file check to script

ci/check_installed_data.py

@@ -0,0 +1,20 @@
+#!/usr/bin/env python
+# Check that installed package contains everything we expect
+
+
+import os
+
+from jupyterhub._data import DATA_FILES_PATH
+
+print("Checking jupyterhub._data")
+print(f"DATA_FILES_PATH={DATA_FILES_PATH}")
+assert os.path.exists(DATA_FILES_PATH), DATA_FILES_PATH
+for subpath in (
+    "templates/page.html",
+    "static/css/style.min.css",
+    "static/components/jquery/dist/jquery.js",
+    "static/js/admin-react.js",
+):
+    path = os.path.join(DATA_FILES_PATH, subpath)
+    assert os.path.exists(path), path
+print("OK")