chore(PP 1): move output showing into driver

Method to solve equation passes result to driver class and driver shows
output to user.
Add more strich check for value of function at point mid
feat(Sudoku): add class for sudoku solver

Class includes empty constructor, constructor with predefined puzzle and
method to check validity of digit in given cell
feat(Sudoku): add table which shows given cells and cells to fill
feat(Sudoku): add method to check validity of digit in given cell

Method takes digit and position and checks if that digit can be put in
that position.
feat(Sudoku): add method that checks if whole puzzle is solved
feat(Sudoku): add method that shows all numbers available in the cell
feat(Sudoku): add method to recursively solve puzzle
feat(Sudoku): add public method for solving puzzle
feat(Sudoku): add toString method
feat(SudokuTester): add tester for Sudoku solver