nbtest dependencies

setup.py

@@ -111,7 +111,7 @@ def default_setup_args(*, version):
 extras_require = dict()
 full_requirements = ['matplotlib', 'autogluon.tabular', 'torch', 'xgboost']
 notebook_requirements = full_requirements + ['fairlearn']
-test_requirements = notebook_requirements + ["tox", "pytest", "pytest-cov", 'flake8', 'cchardet',
+test_requirements = notebook_requirements + ["tox", "pytest", "pytest-cov", 'flake8', 'chardet', 'cchardet',
                                              'linkcheckmd', 'ipynbcompress', 'nbtest']
 
 full_requirements = list(set(full_requirements))