First commit
Updated the diagram class sudoku
* Added the config.xml

* Added the config_xml, menu_console class
	- Added the unittest
Updated the unit test for config_xml and menu_console classes
- Applied changed according to suggestion of code review

	* Added local variables in the unit test
	* Added a new config.xml in order to use in the unittest
	* Added new validation for the path (exist_path())
	* Added some comments in order to separate the constants variable according their functionality

- Added comment to methods according to PEP 257
- Updated the methods in order to keep the standard PEP 8
- Added the utils module in order to reuse some methods in other classes
Added the implementation to solve sudoku using the algorithm Norvig

	* Added the AlgorithmBase Strategy interface
	* Added the AlgorithmSolver context
	* Added the AlgorithmNorving class
	* Added the unittest for the AlgorithmNorvig solver method
Updated the AlgorithmNorvig class

	* Added comments according to PEP 257
	* Renamed some variables in order to have variable more understandable
Merge pull request #5 from carlosgonzales/master

Applied changes according to code review in the AlgorithmNorvig class