doctest to unittest

[dizak]

ab2a2de on branch UPD#64

Description

doctests do not work after py extension is removed from the python scripts. Also, these are the basic level math functions that would be suitable for that kind of tests.

Steps to reproduce

1. Run python -m doctest on any of the mothulity scripts

Expected behaviour

Passing doctests

Actual behaviour

Failing doctest mostly due to undefined variables since the tested functions self-reference fails without py extension.

[dizak]

mothulity scripts are not importable after removal of py extension. Probably of the functions besides main from the script should be moved to utilities or other part of the module and the tests should be converted.