fix tags

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

priv/repo/migrations/20180110093906_create_events_tags.exs

@@ -0,0 +1,10 @@
+defmodule Eventos.Repo.Migrations.CreateEventsTags do
+  use Ecto.Migration
+
+  def change do
+    create table(:events_tags, primary_key: false) do
+      add :event_id, references(:events)
+      add :tag_id, references(:tags)
+    end
+  end
+end