Add "force" option for compare-file-text

[kpaulisse]

Overview

This pull request modifies the --compare-file-text option, which was previously just a binary option, to accept an additional parameter. There are now 3 behaviors:

• --compare-file-text -- Like before, enables the feature
• --no-compare-file-text -- Like before, disables the feature
• --compare-file-text=force -- New! Enables the feature, and doesn't let it be auto-disabled

We need this behavior because we're using --catalog-only in our workflow, and this currently auto-disables the feature because the second catalog in the non-existent diff is a "NoOp" catalog. With this change, our generated catalog will be populated with the content of static files rather than a reference to them, which is what we want.

I chose this implementation because it preserves existing behavior while still not introducing yet another command line argument. I added an integration test for this as well.

Checklist

• Make sure that all of the tests pass, and fix any that don't. Just run rake in your checkout directory, or review the CI job triggered whenever you push to a pull request.
• Make sure that there is 100% test coverage by running rake coverage:spec or ignoring untestable sections of code with # :nocov comments. If you need help getting to 100% coverage please ask; however, don't just submit code with no tests.
• If you have added a new command line option, we would greatly appreciate a corresponding integration test that exercises it from start to finish. This is optional but recommended.

[ahayworth]

Seems alright to me - like you mentioned in the docs: if you know what you're doing and want to force it, then we can let you! 😄