8.5.1 to 8.6.1 upgrade failure.

[vassilvk]

Steps to reproduce:

1. Upgrade a sameersbn/gitlab setup from version 8.5.1 to 8.6.1.

Observed behavior:
The migrations kick off and then fail with the following message:

StandardError: An error has occurred, all later migrations canceled:

You must enable the pg_trgm extension. You can do so by running "CREATE EXTENSION pg_trgm;" as a PostgreSQL super user, this must be done for every GitLab database. For more information see http://www.postgresql.org/docs/current/static/sql-createextension.html

This same issue has been observed in other GitLab Docker implementations:
https://gitlab.com/gitlab-org/omnibus-gitlab/issues/1185

[sameersbn]

Please see #39 (comment)
If you have based your setup on /~https://github.com/sameersbn/docker-gitlab/blob/master/docker-compose.yml then please add the following line /~https://github.com/sameersbn/docker-gitlab/blob/master/docker-compose.yml#L8 and recreate the containers.

[veggiemonk]

@sameersbn Had the same problem and adding the pd_trgm extension to the docker-compose.yml worked! Thanks!

[vassilvk]

This worked, @sameersbn - thanks!