Initial invites support + tests.

priv/repo/migrations/20180612110515_create_user_invite_tokens.exs

@@ -0,0 +1,12 @@
+defmodule Pleroma.Repo.Migrations.CreateUserInviteTokens do
+  use Ecto.Migration
+
+  def change do
+    create table(:user_invite_tokens) do
+      add :token, :string
+      add :used, :boolean, default: false
+
+      timestamps()
+    end
+  end
+end