Allow to edit account email and delete account

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

priv/repo/migrations/20200210100910_add_unconfirmed_email_to_users_table.exs

@@ -0,0 +1,9 @@
+defmodule Mobilizon.Storage.Repo.Migrations.AddUnconfirmedEmailToUsersTable do
+  use Ecto.Migration
+
+  def change do
+    alter table(:users) do
+      add(:unconfirmed_email, :string)
+    end
+  end
+end