[Chore] Implement test for the services

[olivierobert]

Issue

Automated tests do not cover the core business logic (CSV upload, scraping).

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 services should be covered:

• CSV parsing
• Keyword scraping

[!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.

[manojpanchal90]

@olivierobert Push initial Spec to the PR. I am still working on remaining specs. Here is the latest PR https://github.com/manojpanchal90/nimbletest/pull/8