Fix-up docstrings after Connection() signature change.

Author: dhermes

packages/google-cloud-dns/google/cloud/dns/connection.py

@@ -18,7 +18,11 @@
 
 
 class Connection(_http.JSONConnection):
-    """A connection to Google Cloud DNS via the JSON REST API."""
+    """A connection to Google Cloud DNS via the JSON REST API.
+
+    :type client: :class:`~google.cloud.dns.client.Client`
+    :param client: The client that owns the current connection.
+    """
 
     API_BASE_URL = 'https://www.googleapis.com'
     """The base of the API call URL."""