Make the condition for advancing be 15 finished students.

src/hubbleds/pages/04-explore-data/__init__.py

@@ -108,7 +108,7 @@ def load_class_data():
         else:
             class_data_points = class_measurements
             ids = [int(id) for id in np.unique([m.student_id for m in class_measurements])]
-            ready = len(class_measurements) >= 60
+            ready = len(class_measurements) >= 5 * 15
             if ready:
                 ids = [int(id) for id in np.unique([m.student_id for m in class_measurements])]
                 student_ids.set(ids)