Fixes #3274 : Add migration script to add "All nodes" group

[VinceMacBuche]

Linked to http://www.rudder-project.org/redmine/issues/3274

To be merged in master

[fanf]

I think that we don't want to add the group "All" on a migration. That group is here to speed-up the first steps on using Rudder, and if you are doing a migration, then clearly you are past these steps.

And so, we should not add that pull request.

[jooooooon]

fanf wrote:

I think that we don't want to add the group "All" on a migration. That group is here to speed-up the first steps on using Rudder, and if you are doing a migration, then clearly you are past these steps.

Agreed. We mustn't mess with existing installs.