Fix for python v3.9 and older

warden_server/test_warden_server.py

@@ -15,7 +15,7 @@ import warden_server
 if sys.version_info >= (3, 10):
     import unittest
 else:
-    import unittest2
+    import unittest2 as unittest
 
 if sys.version_info[0] >= 3:
     from io import StringIO