update link to github pages to point to most recent version (#640)

Author: Chris Cho

conf.py

@@ -73,7 +73,7 @@
     'kafka-21-javadoc': ('https://kafka.apache.org/21/javadoc/org/apache/kafka%s', ''),
     'csharp-docs': ('http://mongodb.github.io/mongo-csharp-driver/2.10%s', ''),
     'node-docs': ('http://mongodb.github.io/node-mongodb-native/3.5%s', ''),
-    'scala-docs': ('http://mongodb.github.io/mongo-scala-driver/2.8%s', ''),
+    'scala-docs': ('http://mongodb.github.io/mongo-scala-driver/2.9%s', ''),
     'aws-docs': ('https://docs.aws.amazon.com/%s', ''),
     'wikipedia': ('https://en.wikipedia.org/wiki/%s', ''),
     'community-support': ('https://www.mongodb.com/community-support-resources%s', ''),

source/scala.txt

@@ -55,8 +55,8 @@ Connect to MongoDB Atlas
    val db: MongoDatabase = client.getDatabase("test")
 
 
-See `Connecting <http://mongodb.github.io/mongo-scala-driver/2.6/reference/connecting/>`__
-for more ways to connect.
+See our guide on :scala-docs:`Connecting </reference/connecting>` for more 
+ways to connect.
 
 
 Compatibility