This change includes unit tests for YoloDetection class and for functions stored in utils.py.
During my implementation I encountered some problems:

• I wasn't able to install yolov5 in version 5.0.3, so I changed it to 5.0.5 - please let me know if that ok
• When executing code of image-processing module from tests.py the relative config path was read as if it was from tests.py - I changed it to absolute path (as I checked it worked fine in pycharm when executing main module) - please let me know if you ok with that
• I use some images in unit tests - I to add them to github I have to edit .gitignore file - also please let me known what do you think about this case