Add tests for checking of workbench_integration module version and add additional error handling/messaging in code

[whikloj]

Link to Github issue or other discussion

No issue, just a couple more tests and some additional error checking

What does this PR do?

Adds some unit tests of validating the islandora_workbench_integration version

What changes were made?

Tests added, also wrapped the response.json() in a try except and capture some Exceptions.

How to test / verify this PR?

This should not affect any existing behaviour

Interested Parties

@mjordan

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Checklist

• Before opening this PR, have you opened an issue explaining what you want to to do?
• Have you included some configuration and/or CSV files useful for testing this PR?
• Have you written unit or integration tests if applicable?
• Does the code added in this PR require a version of Python that is higher than the current minimum version?
• If the changes in this PR require an additional Python library, have you included it in setup.py?
• If the changes in this PR add a new configuration option, have you provided a default for when the option is not present in the .yml file?