Started on graph.py restructuring (in graph2.py)

Former-commit-id: 70817bdafa57a9c39de68d46967414519c5714f8

pyKADMOS/sample/graph.py

@@ -52,6 +52,7 @@ from pyKADMOS.packages.D3_vispack import D3_vispack as D3vp
 # Setting up logger
 logger = logging.getLogger(__name__)
+# Setting up KADMOS file types and the corresponding extensions
 file_types = ['cmdows', 'kdms', 'graphml']
 file_extensions = ['xml', 'kdms', 'graphml']