Feat: Add unit testing dependencies

[albendz]

Add Junit 5 and Mockk test dependencies with simple test

Contributor checklist

• This pull request is on a separate branch and not the main branch

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Description

This change adds dependencies to enable writing unit tests including JUnit 5, a dependency to support use of JUnit 5 for android tests, and MockK following details and discussion from #181

I added a simple test for a utility class as an example.

I ran the following commands to test:

• ./gradlew test
• ./gradlew check

For each of these, I verified they fail when expected (set assertions to be incorrect) and pass otherwise.

Once this change is merged, there are a few follow ups needed - I can create issues for these so they can be done later:

• Test code conventions (naming, organization, etc.)
• Adding tests to automated PR checks
• Adding code coverage tooling and automated PR code coverage checks
• Adding example tests with mocking

Related issue

• Set up local unit testing in Scribe Android App #181

[github-actions]

Thank you for the pull request!

The Scribe team will do our best to address your contribution as soon as we can. The following is a checklist for maintainers to make sure this process goes as well as possible. Feel free to address the points below yourself in further commits if you realize that actions are needed :)

If you're not already a member of our public Matrix community, please consider joining! We'd suggest using Element as your Matrix client, and definitely join the General and Android rooms once you're in. Also consider joining our bi-weekly Saturday dev syncs. It'd be great to have you!

Maintainer checklist

• The commit messages for the remote branch should be checked to make sure the contributor's email is set up correctly so that they receive credit for their contribution

  • The contributor's name and icon in remote commits should be the same as what appears in the PR
  • If there's a mismatch, the contributor needs to make sure that the email they use for GitHub matches what they have for git config user.email in their local Scribe-Android repo

• The linting and formatting workflows within the PR checks do not indicate new errors in the files changed

• The CHANGELOG has been updated with a description of the changes for the upcoming release and the corresponding issue (if necessary)

[angrezichatterbox]

Thanks for the PR @albendz. Everything looks good to me :)

[andrewtavis]

Thanks for this, @albendz! Really great to have the testing setup for Scribe-Android progressing so early on in its life 😊 Would be great if you could make the issues you discussed in the commit message!

[albendz]

Thank you! I've created the following issues for next steps:
#194
#195
#196
#197

[andrewtavis]

Thanks so much, @albendz! Really amazing 😊