[Chore] Improve the test implementations

[malparty]

Issue

• Automated tests do not cover the core business logic (data scraping, dashboard tto retrieve the keywords).
• Some tests are not self-descriptive (e.g. application-api/tests/Feature/AppTest.php, in opposition to the Auth/AuthenticationTest.php tests that have self-descriptive names)

Expected

While 100% test coverage is not required for this code challenge, all critical paths of the application should be unit-tested (and, ideally, UI-tested). So the following should be covered:

• CSV parsing (application-frontend, not only the validation of the file)
• Keyword scraping (spider-api)
• Keyword listing (application-frontend)

Note There is a bit of a challenge to implement tests for a service that generates HTTP requests. Hence, it is an expected part of the submission for us to assess your skills in writing challenging tests.

[mgmgpyaesonewin]

https://github.com/mgmgpyaesonewin/web-crawler-assignment/pull/17

[mgmgpyaesonewin]

https://github.com/mgmgpyaesonewin/web-crawler-assignment/pull/21