[lldb] remove unittest2

Author: charles-zablit

lldb/packages/Python/lldbsuite/test/lldbplaygroundrepl.py

@@ -120,4 +120,4 @@ def test_playgrounds(self):
     import atexit
     lldb.SBDebugger.Initialize()
     atexit.register(lldb.SBDebugger.Terminate)
-    unittest2.main()
+    unittest.main()

lldb/test/API/python_api/sbvalue_updates/TestSBValueUpdates.py

@@ -66,4 +66,4 @@ def do_test(self):
     import atexit
     lldb.SBDebugger.Initialize()
     atexit.register(lldb.SBDebugger.Terminate)
-    unittest2.main()
+    unittest.main()