Add BFS, DFS, bfs, dfs, move graph_demo() to a seperate file . All tests passed.

thu_dsa/chp6/testGraphMatrix.cpp

@@ -9,7 +9,7 @@ void test_vertex_insert();
 void test_vertex_delete();
 void test_edge_insert();
 
-int main(){
+int GraphMatrix_test_main(){
 	cout << "Running tests" << endl;
 
 	test_constructor();