Implementation of Unit Tests

[the-siegfried]

Is your feature request related to a problem? Please describe:
Currently the project does not have any unit tests. The implementation of these tests include but are not limited to the following benefits:

• Ensures that any future development does not introduce any breaking changes.
• Enables developers and testers to save time when trying to identify bugs.
• Ensures high quality product development.

Describe the solution you'd like:
Implementation of a test-suite within the modules library (/modules/tests), testing each of the modules and methods in isolation. And the implementation of a functional test suite at the application layer (TorCrawl.py/tests) in order to test all the possible user workflows of the application to ensure the conformity of the project with its requirements.

Some test frameworks that would be suitable for this use-case are; unittest, pytest, or clever-sheep (possibly overkill).