Tox fixes

gui/display.py

@@ -26,7 +26,7 @@ from gui.cachingImageList import CachingImageList
 
 
 class Display(wx.ListCtrl):
-    DEFAULT_COLS =  None
+    DEFAULT_COLS = None
 
     def __init__(self, parent, size=wx.DefaultSize, style=0):
 

gui/mainFrame.py

@@ -90,7 +90,7 @@ if 'wxMac' not in wx.PlatformInfo or ('wxMac' in wx.PlatformInfo and wx.VERSION
 
         disableOverrideEditor = False
     except ImportError as e:
-        AttributeEditor =  None
+        AttributeEditor = None
         print("Error loading Attribute Editor: %s.\nAccess to Attribute Editor is disabled." % e.message)
         disableOverrideEditor = True