Make aws usage more clear in README

[carpawell]

Is your feature request related to a problem? Please describe.

I'm always frustrated when I have to figure out why tests do not start and no readable information can be found after the reason is clear. My problem was in the outdated aws cli that did not have some features. It was installed locally (I am almost sure I did it to pass tests some years ago) and I had no idea what the problem was. @evgeniiz321 said tests do check aws presence and install if it is needed but there is no info about it in README and also there are no checks about its version.

Describe the solution you'd like

Install aws locally (in the venv or some gitignored path; not OS-wise) always to be sure its version is suitable for tests.

Describe alternatives you've considered

1. Mark version in README.
2. Check local version if any is found.

Additional context