Update for transaction 2.0.3 (extended_info -> extension)

setup.py

@@ -141,7 +141,7 @@ setup(name="ZODB",
         'persistent >= 4.2.0',
         'BTrees >= 4.2.0',
         'ZConfig',
-        'transaction >= 2.0.0',
+        'transaction >= 2.0.3',
         'six',
         'zc.lockfile',
         'zope.interface',

src/ZODB/Connection.py

@@ -462,7 +462,7 @@ class Connection(ExportImport, object):
         meta_data = TransactionMetaData(
             transaction.user,
             transaction.description,
-            transaction.extended_info)
+            transaction.extension)
         transaction.set_data(self, meta_data)
 
         # _creating is a list of oids of new objects, which is used to

src/ZODB/DB.py

@@ -1040,7 +1040,7 @@ class TransactionalUndo(object):
         tdata = TransactionMetaData(
             transaction.user,
             transaction.description,
-            transaction.extended_info)
+            transaction.extension)
         transaction.set_data(self, tdata)
         self._storage.tpc_begin(tdata)