Add library into Maven for test.

I will use the following framework to execute my tests :
-JUnit 4
-Fest Assert
First definition of the Levenshtein Algorithm.

I've created a class that implements the Levenshtein algorithm (empty for the moment) and an other class to test it.
Implement getter and setter cell value.
Implements the calculate cell function.

This method is a part of the Levenshtein algorithm. To complete the algorithm, an other method must call this methods for all cells.