Make tests great again !

(Also use only one field for public/private key pem)
Signed-off-by: Thomas Citharel <tcit@tcit.fr>

priv/repo/migrations/20180614094653_make_shared_inbox_url_nullable.exs

@@ -0,0 +1,15 @@
+defmodule Eventos.Repo.Migrations.MakeSharedInboxUrlNullable do
+  use Ecto.Migration
+
+  def up do
+    alter table(:actors) do
+      modify :shared_inbox_url, :string, null: true, default: nil
+    end
+  end
+
+  def down do
+    alter table(:actors) do
+      add :shared_inbox_url, :string, null: false, default: ""
+    end
+  end
+end