3.0.0 -> 3.1.0
--------------
* Run rake task:
    bundle exec rake cartodb:overlays:create_overlays

    if the task is run more than one time (because something happened) a flag to remove previous overlays should be pass

    bundle exec rake cartodb:overlays:create_overlays[true]

    this will remove all the overlays for visualizations so it MUST NOT be called after visualization overlays has been customized

2.x -> 3.0.0
------------
* Install CartoDB extension version 0.3.x
* Run rake tasks:
  - bundle exec rake cartodb:db:create_default_vis_permissions
  - bundle exec rake cartodb:db:populate_permission_entity_id


General notes
-------------

NOTES:
 - Redis server must be listening on the configured
   port (see config/app_config.yml) for some of the
   steps below to work
 - Rails must be restarted after an upgrade


Standard migration (default)
----------------------------

Unless stated otherwise, assume any new CartoDB release requires calling these commands:

 $ bundle exec rake db:migrate


Mandatory migration
-------------------

Versions marked at the NEWS.md as requiring this migration must:

 - ensure the required version of cartodb-postgresql extension
   (see README.md) is installed on the user database hosts

 - run all this commands:

 $ bundle exec rake db:migrate
 $ bundle exec rake cartodb:db:reset_trigger_check_quota
 $ bundle exec rake cartodb:db:load_functions
 $ bundle exec rake cartodb:db:create_schemas