migrations: add index creation migration and recipients_to/cc removal migration

priv/repo/migrations/20180829182612_activities_add_to_cc_indices.exs

@@ -0,0 +1,8 @@
+defmodule Pleroma.Repo.Migrations.ActivitiesAddToCcIndices do
+  use Ecto.Migration
+
+  def change do
+    create index(:activities, ["(data->'to')"], name: :activities_to_index, using: :gin)
+    create index(:activities, ["(data->'cc')"], name: :activities_cc_index, using: :gin)
+  end
+end

priv/repo/migrations/20180829183529_remove_recipients_to_and_cc_fields_from_activities.exs

@@ -0,0 +1,10 @@
+defmodule Pleroma.Repo.Migrations.RemoveRecipientsToAndCcFieldsFromActivities do
+  use Ecto.Migration
+
+  def change do
+    alter table(:activities) do
+      remove :recipients_to
+      remove :recipients_cc
+    end
+  end
+end