Introduce relay

Signed-off-by: Thomas Citharel <tcit@tcit.fr>

priv/repo/migrations/20190806131306_add_url_to_follows_and_move_to_uuid.exs

@@ -0,0 +1,21 @@
+defmodule Mobilizon.Repo.Migrations.AddUrlToFollowsAndMoveToUuid do
+  use Ecto.Migration
+
+  def up do
+    alter table(:followers, primary_key: false) do
+      remove(:score)
+      remove(:id)
+      add(:id, :uuid, primary_key: true)
+      add(:url, :string, null: false)
+    end
+  end
+
+  def down do
+    alter table(:followers, primary_key: true) do
+      add(:score, :integer, default: 1000)
+      remove(:id)
+      add(:id, :serial, primary_key: true)
+      remove(:url)
+    end
+  end
+end