Improve test coverage

↩️ Back to the main Herb.jl Hacktoberfest issue

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This repository currently has 28% test coverage. It shouldn't take too much work to bring this close to 100%. The absolute number of lines missing coverage is not high, but the code might look a little weird upon first examining it. Plan to take a few minutes to familiarize yourself with the interpret function in particular.

Suggested steps:

1. If you're new to Herb, please take a look at our getting started guide and CONTRIBUTING.md.
2. Check the current test coverage on Codecov.
3. Following the CONTRIBUTING.md guide, set up your own fork of HerbInterpret and take a look at the existing tests.
4. We would suggest creating two new files, each with a test set: one for deprecations and one for the interpret(...)/call_func(...) function tests
   • For the deprecated functions missing coverage, @test_deprecated is sufficient.
   • For the interpret/call_func tests, aim to increase the coverage to 100%! (but any increase is much appreciated 🤗 )
5. Open a PR with your new tests to verify CI passes and that the coverage is what you expect

Don't hesitate to reach out here for any clarifications. Happy hacking!