Update flake8 for the deploy check

Author: mdmintz

setup.py

@@ -36,7 +36,7 @@
     reply = str(input_method(confirm_text)).lower().strip()
     if reply == "yes":
         print("\n*** Checking code health with flake8:\n")
-        os.system("python -m pip install 'flake8==3.9.2'")
+        os.system("python -m pip install 'flake8==4.0.1'")
         flake8_status = os.system("flake8 --exclude=recordings,temp")
         if flake8_status != 0:
             print("\nWARNING! Fix flake8 issues before publishing to PyPI!\n")