Fixed driver/session config bug

Author: technige

neo4j/v1/session.py

@@ -99,7 +99,7 @@ def session(self, **config):
             >>> session = driver.session()
 
         """
-        return Session(connect(self.host, self.port, **config))
+        return Session(connect(self.host, self.port, **dict(self.config, **config)))
 
 
 class Result(list):