Python: Make test 2/3 compatible.

Author: markshannon

python/ql/test/library-tests/PointsTo/extensions/Extend.expected

@@ -6,7 +6,7 @@
 | test.py:8:5:8:5 | ControlFlowNode for IntegerLiteral | int 3 |
 | test.py:8:7:8:7 | ControlFlowNode for IntegerLiteral | int 4 |
 | test.py:10:1:10:2 | ControlFlowNode for a3 | int 3 |
-| test.py:10:6:10:7 | ControlFlowNode for Str | str u'' |
+| test.py:10:6:10:7 | ControlFlowNode for Tuple | Tuple |
 | test.py:10:6:10:13 | ControlFlowNode for Attribute | int 3 |
 | test.py:11:1:11:2 | ControlFlowNode for a4 | int 4 |
 | test.py:11:6:11:10 | ControlFlowNode for False | bool False |

python/ql/test/library-tests/PointsTo/extensions/test.py

@@ -7,7 +7,7 @@
 #Make sure values exist in DB
 1,2,3,4
 
-a3 = "".three
+a3 = ().three
 a4 = False.four
 
 a3