Refresh all docs (#298)

Change the discovery query to fetch all discovery docs, not just the
preferred ones.
diff --git a/docs/dyn/sqladmin_v1beta3.backupRuns.html b/docs/dyn/sqladmin_v1beta3.backupRuns.html
index 093479f..995235e 100644
--- a/docs/dyn/sqladmin_v1beta3.backupRuns.html
+++ b/docs/dyn/sqladmin_v1beta3.backupRuns.html
@@ -92,7 +92,7 @@
   project: string, Project ID of the project that contains the instance. (required)
   instance: string, Cloud SQL instance ID. This does not include the project ID. (required)
   backupConfiguration: string, Identifier for the backup configuration. This gets generated automatically when a backup configuration is created. (required)
-  dueTime: string, The time when this run is due to start in RFC 3339 format, for example 2012-11-15T16:19:00.094Z. (required)
+  dueTime: string, The start time of the four-hour backup window. The backup can occur any time in the window. The time is in RFC 3339 format, for example 2012-11-15T16:19:00.094Z. (required)
 
 Returns:
   An object of the form: