Updates example using old-style hostname and port specification to use the standard connection string format.

Author: lyndsysimon

doc/tutorial.rst

@@ -45,7 +45,7 @@ specify the host and port explicitly, as follows:
 
 .. doctest::
 
- >>> client = MongoClient('localhost', 27017)
+ >>> client = MongoClient('mongodb://localhost:27017/')
 
 Getting a Database
 ------------------