rollout_ui is incompatible with rollout > 2.1.0

[sophiedeziel]

I updated all my gems this week and I had a problem with rollout and rollout UI.

That error showed up in the view:

undefined method `join' for #<Set: {}>
/Users/sdeziel/.rvm/gems/ruby-2.2.4@express/gems/rollout_ui-0.3.0/lib/rollout_ui/engine/app/views/rollout_ui/features/_feature.html.erb:31

The faulty line:

<input class="users" type="text" name="users[]" value="<%= feature.user_ids.join(",") %>" data-placeholder="Enter User ID" />

I looked into rollout changes and since v2.2.1, Set is used instead of Array for users.
fetlife/rollout@5b2615e

[sarahjschultz]

+1 to this issue -- seeing it in our project as well.