Run tests in separate processes

[PokhodenkoSA]

I did not find parameter in unittest for excluding tests from run. I know that pytest has exclude parameter. Moving to PyTest is separate task. So the solution now is rough because it requires to support the list of tests in 2 files. It is just for checking the solution. I will try to find exclude flag for unittest or will try to move to pytest.

[Vyacheslav-Smirnov]

If these modules contains all tests that should be executed, then I am ok with this solution for now. But guess we need to change it in future.

[PokhodenkoSA]

It runs all tests as previous just runs it in separate processes. I will merge it. More sophisticated solutions are welcome.