Improve "brython" compatibility for Python 3.9 users

Author: mdmintz

requirements.txt

@@ -58,7 +58,7 @@ importlib-metadata==2.0.0
 virtualenv>=20.0.33
 pymysql==0.10.1
 coverage==5.3
-brython==3.8.10
+brython==3.9.0
 pyotp==2.4.0
 boto==2.49.0
 cffi==1.14.3

setup.py

@@ -152,7 +152,7 @@
         'virtualenv>=20.0.33',  # Sync with importlib-metadata and pathlib2
         'pymysql==0.10.1',
         'coverage==5.3',
-        'brython==3.8.10',
+        'brython==3.9.0',
         'pyotp==2.4.0',
         'boto==2.49.0',
         'cffi==1.14.3',