remove duplicate lines

ref https://github.com/stack-of-tasks/dynamic-graph-python/pull/34#discussion_r340106255

src/dynamic_graph/entity.py

@@ -18,8 +18,6 @@ if 'display' not in globals().keys():
 
 
 # --- FACTORY ------------------------------------------------------------------
-# --- FACTORY ------------------------------------------------------------------
-# --- FACTORY ------------------------------------------------------------------
 
 
 class PyEntityFactoryClass(type):
@@ -69,8 +67,6 @@ def updateEntityClasses(dictionary):
 
 
 # --- ENTITY -------------------------------------------------------------------
-# --- ENTITY -------------------------------------------------------------------
-# --- ENTITY -------------------------------------------------------------------
 
 
 class VerbosityLevel(Enum):