Remove duplicate migration

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

priv/repo/migrations/20180126094416_add_avatar_and_banner_to_account.exs

@@ -1,10 +0,0 @@
-defmodule Eventos.Repo.Migrations.AddAvatarAndBannerToAccount do
-  use Ecto.Migration
-
-  def change do
-    alter table(:accounts) do
-      add :avatar_url, :string, null: true
-      add :banner_url, :string, null: true
-    end
-  end
-end