Fix specs, add local marker to actitivies.

priv/repo/migrations/20170502083023_add_local_field_to_activities.exs

@@ -0,0 +1,11 @@
+defmodule Pleroma.Repo.Migrations.AddLocalFieldToActivities do
+  use Ecto.Migration
+
+  def change do
+    alter table(:activities) do
+      add :local, :boolean, default: true
+    end
+
+    create index(:activities, [:local])
+  end
+end