update gettext schema and use macros for cannery app

lib/cannery_web/controllers/error_json.ex

@@ -1,5 +1,5 @@
 defmodule CanneryWeb.ErrorJSON do
-  import CanneryWeb.Gettext
+  use Gettext, backend: CanneryWeb.Gettext
 
   def render(template, _assigns) do
     error_string =

lib/cannery_web/controllers/user_auth.ex

@@ -4,9 +4,9 @@ defmodule CanneryWeb.UserAuth do
   """
 
   use CanneryWeb, :verified_routes
+  use Gettext, backend: CanneryWeb.Gettext
   import Plug.Conn
   import Phoenix.Controller
-  import CanneryWeb.Gettext
   alias Cannery.{Accounts, Accounts.User}
 
   # Make the remember me cookie valid for 60 days.

lib/cannery_web/controllers/user_confirmation_controller.ex

@@ -1,7 +1,5 @@
 defmodule CanneryWeb.UserConfirmationController do
   use CanneryWeb, :controller
-
-  import CanneryWeb.Gettext
   alias Cannery.Accounts
 
   def new(conn, _params) do

lib/cannery_web/controllers/user_registration_controller.ex

@@ -1,6 +1,5 @@
 defmodule CanneryWeb.UserRegistrationController do
   use CanneryWeb, :controller
-  import CanneryWeb.Gettext
   alias Cannery.{Accounts, Accounts.Invites}
   alias Ecto.Changeset
 

lib/cannery_web/controllers/user_settings_controller.ex

@@ -1,6 +1,5 @@
 defmodule CanneryWeb.UserSettingsController do
   use CanneryWeb, :controller
-  import CanneryWeb.Gettext
   alias Cannery.Accounts
   alias CanneryWeb.UserAuth