- converted from Python2 code to Python3 code

- in camlib.py, CNCJob class -> generate_from_excellon_by_tool() was
failing in the line to sort the tools due of been unable to compare
between dict's. I replaced that section.

tests/other/destructor_test.py

@@ -8,7 +8,7 @@ class MyObj():
         pass
 
     def __del__(self):
-        print "##### Destroyed ######"
+        print("##### Destroyed ######")
 
 
 def parse():