BUG #13647: Error after upgrade 9.3->9.4: materialized view `foo` has not been populated

The following bug has been logged on the website:

Bug reference:      13647
Logged by:          Benjamin Flesch
Email address:      beni@strivewire.com
PostgreSQL version: 9.4.4
Operating system:   Ubuntu 14.04
Description:        

After upgrading using the ubuntu up_upgradecluser script, the materialized
views are not populated, resulting in errors.

I had to manually perform "REFRESH MATERIALIZED VIEW foo;" in order to fix
this issue.

It would be nice if the upgrade script also refreshed materialized views in
the future.