Issue #9554: Use modern unittest features in test_argparse.

Initial patch by Denver Coneybeare and Radu Voicilas.
diff --git a/Misc/ACKS b/Misc/ACKS
index e9a473e..204fd88 100644
--- a/Misc/ACKS
+++ b/Misc/ACKS
@@ -1399,6 +1399,7 @@
 Pauli Virtanen
 Frank Visser
 Johannes Vogel
+Radu Voicilas
 Alex Volkov
 Martijn Vries
 Sjoerd de Vries
diff --git a/Misc/NEWS b/Misc/NEWS
index dc42be7..9ad35fe 100644
--- a/Misc/NEWS
+++ b/Misc/NEWS
@@ -653,6 +653,9 @@
 Tests
 -----
 
+- Issue #9554: Use modern unittest features in test_argparse. Initial patch by
+  Denver Coneybeare and Radu Voicilas.
+
 - Issue #20155: Changed HTTP method names in failing tests in test_httpservers
   so that packet filtering software (specifically Windows Base Filtering Engine)
   does not interfere with the transaction semantics expected by the tests.