Log sync_repository_task when we run it

This should make it more obvious what our builders are doing

Author: ericholscher

readthedocs/projects/tasks.py

@@ -359,6 +359,11 @@ def run(self, version_pk):  # pylint: disable=arguments-differ
                 update_on_success=False,
                 environment=self.get_rtd_env_vars(),
             )
+            log.info(
+                'Running sync_repository_task: project=%s, version=%s',
+                self.project.slug,
+                self.version.slug,
+            )
 
             with environment:
                 before_vcs.send(sender=self.version, environment=environment)