Add automated tests for cnf and simplify methods.
Solving issue 8.
Remove unnecessary code from logConstructs.
Remove uneccessary code from sudoku and graph coloring files.
Comment logConstruct file.
Fix sat solver for imput false().
Add sat solver tests for basic elements.
Centralize tests in automated_test directory and test.py file.
Adde new sudoku examples in sat tests.
Add code for expected error for sudoku tests and skip them.

Reason:
- possiblity of memory error,
- skipping because test take too long.
Modifi examples code to return only formula.

Reason:
- simplicity.
Loosen fil_condition method that one field can have more values.

Reasons:
- formula is too complex.
- corectness is enshured by row, column and square conditions.
Add method for presenting solution of sudoku example and modify current
print method for sudoku.

Reasons:
- Easyer to check,
- easyer to see.
Add basic examples.
Add example of solving sudoku puzzle.
Add test for sat in system tests and enable sudoku tests.