Script should do the following

• Validate the links of the podcasts (whether they are broken)
• Validate the order of the podcasts in each category (and also categories)

Break the build when either of the above validations fail

file_object in Updater._get_metadata_file() is left unclosed whenever an exception is raised (when the metadata fails a check of any kind). There are loads of examples in the test suite, e.g.

python3 test_updater.py TestUpdater.test_3__update_metadata

will complain "ResourceWarning: unclosed file"

This is not very dangerous but makes it hard to find actual issues in test output (