Run examples in CI

[PokhodenkoSA]

Related #197

Examples now are checked only manually. CI will help to fix regressions in examples.

• Modify scripts for running Python examples in CI
• Building and running Cython examples

[diptorupd]

@oleksandr-pavlyk The issue is worth resolving. The idea is to keep our examples up to date and we can add a Github workflow to do it.

[oleksandr-pavlyk]

@diptorupd We do test examples on Linux in conda-package.yml.

[diptorupd]

@oleksandr-pavlyk 👍