Address deprecation warning for 'itsdangerous.json'

[lbeaufort]

What we’re after

Tests in CircleCI are flagging an issue with Flask where it's using deprecated functionality:

tests/test_sched_e.py::TestScheduleEByCandidateView::test_sort_bad_column
  /home/circleci/repo/venv/lib/python3.7/site-packages/flask/json/__init__.py:211: DeprecationWarning: Importing 'itsdangerous.json' is deprecated and will be removed in ItsDangerous 2.1. Use Python's 'json' module instead.
    rv = _json.dumps(obj, **kwargs)

Action item(s)

• Replicate the issue locally by running Pytest
• Try updating Flask to 1.1.4, or if that doesn't fix it, 2.x (see Update Flask to 2.0.1 (or latest 2.x) #4958)

Completion criteria

• Warning no longer shows when running tests

[pkfec]

Updating flask to a minor version 1.1.4 didn't make any difference. And when updated to major version 2.0.1, pytest failed due to *other package dependencies.

While running pytest in circleci and local env, below 3 different deprecation warning messages appear on the console/terminal. Had to pin packages to a specific versions to address the depreciation warnings.

1. /home/circleci/repo/venv/lib/python3.7/site-packages/flask/json/__init__.py:211: DeprecationWarning: Importing itsdangerous.json is deprecated and will be removed in ItsDangerous 2.1. Use Python's json module instead. rv = _json.dumps(obj, **kwargs)

• In requirements.txt pinned itsdangerous==1.1.0

2: /home/circleci/repo/venv/lib/python3.7/site-packages/flake8/plugins/manager.py:254: DeprecationWarning: SelectableGroups dict interface is deprecated. Use select. eps = importlib_metadata.entry_points().get(self.namespace, ())
see here for more details: python/importlib_metadata#298

• In requirements.txt pinned importlib-metadata==3.10.1

3: /Users/pkasireddy/.pyenv/versions/3.7.10/envs/test-4950/lib/python3.7/site-packages/jsonschema/validators.py:197: DeprecationWarning: Passing a schema to Validator.iter_errors is deprecated and will be removed in a future release. Call validator.evolve(schema=new_schema).iter_errors(...) instead

• In requirements.txt pinned jsonschema==3.2.0