Refactor CylinderShaft class and fix display call

Author: ndem0

bladex/cylinder_shaft.py

@@ -1,10 +1,10 @@
-import OCC.Core.TopoDS
+""" Cylinder Shaft """
 from OCC.Display.SimpleGui import init_display
 from OCC.Core.BRepPrimAPI import BRepPrimAPI_MakeCylinder
 from OCC.Core.gp import gp_Pnt, gp_Dir, gp_Ax2
 
 
-class CylinderShaft(object):
+class CylinderShaft:
     """
     Cylinder shaft construction.
 
@@ -50,4 +50,4 @@ def display(self):
         shaft_solid = self.generate_solid()
         display, start_display = init_display()[:2]
         display.DisplayShape(shaft_solid, update=True)
-        start_display()
+        start_display()