py3: define xrange for python3

this is done in files where the xrange is used.
replace this with range once python2 is not supported anymore.
issue 0000995

src/Mod/Path/PathScripts/PathDrilling.py

@@ -23,6 +23,7 @@
 # ***************************************************************************
 
 from __future__ import print_function
+import sys
 import FreeCAD
 # from FreeCAD import Vector
 import Path
@@ -35,6 +36,10 @@ from PathScripts.PathUtils import fmt
 import ArchPanel
 
 
+# xrange is not available in python3
+if sys.version_info.major >= 3:
+    xrange = range
+
 LOG_MODULE = 'PathDrilling'
 PathLog.setLevel(PathLog.Level.INFO, LOG_MODULE)
 PathLog.trackModule('PathDrilling')