Clear cache when update to 6.1

doc/update/6.0-to-6.1.md

@@ -54,12 +54,13 @@ sudo -u git -H bundle install --without development test mysql --deployment
 sudo -u git -H bundle exec rake db:migrate RAILS_ENV=production
 sudo -u git -H bundle exec rake migrate_iids RAILS_ENV=production
 sudo -u git -H bundle exec rake assets:precompile RAILS_ENV=production
+sudo -u git -H bundle exec rake cache:clear RAILS_ENV=production
 ```
 ### 5. Update config files
-* Make `/home/git/gitlab/config/gitlab.yml` same as https://github.com/gitlabhq/gitlabhq/blob/5-4-stable/config/gitlab.yml.example but with your settings.
-* Make `/home/git/gitlab/config/unicorn.rb` same as https://github.com/gitlabhq/gitlabhq/blob/5-4-stable/config/unicorn.rb.example but with your settings.
+* Make `/home/git/gitlab/config/gitlab.yml` same as https://github.com/gitlabhq/gitlabhq/blob/6-1-stable/config/gitlab.yml.example but with your settings.
+* Make `/home/git/gitlab/config/unicorn.rb` same as https://github.com/gitlabhq/gitlabhq/blob/6-1-stable/config/unicorn.rb.example but with your settings.
 ### 6. Update Init script