Introduce group basic federation, event new page and notifications

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

priv/repo/migrations/20200526131523_create_user_settings.exs

@@ -0,0 +1,15 @@
+defmodule Mobilizon.Repo.Migrations.CreateUserSettings do
+  use Ecto.Migration
+
+  def change do
+    create table(:user_settings, primary_key: false) do
+      add(:timezone, :string)
+      add(:notification_on_day, :boolean)
+      add(:notification_each_week, :boolean)
+      add(:notification_before_event, :boolean)
+      add(:user_id, references(:users, on_delete: :delete_all), primary_key: true)
+
+      timestamps()
+    end
+  end
+end