Changed Location class to Coordinate
Added Cell class to represent a Cell in a Map
Added Node class to represent a Node in a Graph
Added a Map class to represent a Map
Added a Graph class to represent a Graph
Added a Graph Generator class to generate a Graph from a Map
Altered the MapGenerator class to return a Map instead of an int[][]

Added a MapGeneratorTest and a GraphGeneratorTest JUnit classes to do
basic tests on the output of the classes