Improve docs compliance with project

Author: gglanzani

happybase/connection.py

@@ -87,7 +87,13 @@ class Connection(object):
     The optional `use_kerberos` argument allows you to establish a
     secure connection to HBase. This argument requires a buffered
     `transport` protocol. You must first authorize yourself with
-    your KDC by using kinit (e.g. kinit -kt my.keytab user@REALM)
+    your KDC by using `kinit` (e.g. `kinit -kt my.keytab user@REALM`)
+    
+    The optional `sasl_service` argument allows to specify the name of
+    the sasl service.
+    
+    .. versionadded:: 0.9.1
+       `use_kerberos` and `sasl_service` arguments
 
     .. versionadded:: 0.9
        `protocol` argument