Add tests for ChineseCNLocale

[lyl1999]

Pull Request Checklist

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• [ ] 🧪 Added tests for changed code.
• [ ] 🛠️ All tests pass when run locally (run tox or make test to find out!).
• [ ] 🧹 All linting checks pass when run locally (run tox -e lint or make lint to find out!).
• [ ] 📚 Updated documentation for changed code.
• [ ] ⏩ Code is up-to-date with the master branch.

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Description of Changes

Added a simple test for ChineseCNLocale in test_locales.py

[systemcatch]

This is the test that is failing.

  =================================== FAILURES ===================================
  __________________ TestChineseCNLocale.test_format_timeframe ___________________

  self = <tests.test_locales.TestChineseCNLocale object at 0x7f3a008a6130>

      def test_format_timeframe(self):
          assert self.locale._format_timeframe("now", 0) == "刚才"
  >       assert self.locale._format_timeframe("second", 1) == "1秒"
  E       AssertionError: assert '一秒' == '1秒'
  E         - 1秒
  E         + 一秒

  tests/test_locales.py:1404: AssertionError

[jadchaar]

@lyl1999 we'd love to get these changes merged in, but in order to do that we need the tests to pass. Feel free to re-open this PR if you get around to fixing the tests so that they pass.