Closes #3274 Add BubbleSort unit tests

[aitorfi]

Describe your change:

Added unit tests for the BubbleSort algorithm and removed assert statements from the algorithm class.

References

Closes #3274

Checklist:

• I have read CONTRIBUTING.md.
• This pull request is all my own work -- I have not plagiarized.
• I know that pull requests will not be merged if they fail the automated tests.
• This PR only changes one algorithm file. To ease review, please open separate PRs for separate algorithms.
• All new Java files are placed inside an existing directory.
• All filenames are in all uppercase characters with no spaces or dashes.
• All functions and variable names follow Java naming conventions.
• If this pull request resolves one or more open issues then the commit message contains Fixes: #{$ISSUE_NO}.

[siriak]

Looks good, thanks!