removed old test files

ml/tests/test_cleaner.py

 import pandas as pd
 import datetime
-from tools.cleaner import Cleaner2020
+from tools.cleaner import Cleaner2021
 
 def test_filter_ats_on_ids():
     df = pd.DataFrame([i for i in range(10)], columns=['CitizenId'])
     ids = [i for i in range(5)]
-    filtered_list = Cleaner2020().filter_ats_on_ids(df, ids)
+    filtered_list = Cleaner2021().filter_ats_on_ids(df, ids)
     assert not filtered_list.empty
     assert len(filtered_list) == 5
 
@@ -57,7 +57,7 @@ def test_remove_tainted_histories():
 
 def test_remove_deprecated_device_data():
     df = pd.DataFrame({'DevHMINumber': ['899,997', '899,989', '899,999']})
-    res = Cleaner2020().remove_deprecated_device_data(df)
+    res = Cleaner2021().remove_deprecated_device_data(df)
     assert not res.empty
     assert len(res) == 2