106 add new unit tests

[Barsamyan-D]

Closes: #104, #106, #107, #108, #109

Completed testing with over 65% code coverage, through mainly unit testing and some integration testing.
Added tests for:

• auth repository
• price prediction for data model
• defect detection for data model
• login viewModel
• registration viewModel
• contractor viewModel
• homeowner viewModel
• email viewModel
• listings viewModel