Fix Credo code readability issues

lib/web/email/checker.ex

@@ -3,8 +3,7 @@ defmodule Mobilizon.Web.Email.Checker do
   Provides a function to test emails against a "not so bad" regex.
   """
 
-  # TODO: simplify me!
-  @email_regex ~r/^(([^<>()\[\]\\.,;:\s@"]+(\.[^<>()\[\]\\.,;:\s@"]+)*)|(".+"))@((\[[0-9]{1,3}\.[0-9]{1,3}\.[0-9]{1,3}\.[0-9]{1,3}])|(([a-zA-Z\-0-9]+\.)+[a-zA-Z]{2,}))$/
+  @email_regex ~r/^[\w.!#$%&’*+\-\/=?\^`{|}~]+@[a-zA-Z0-9-]+(\.[a-zA-Z0-9-]+)*$/i
 
   @doc """
   Returns whether the email is valid.

lib/web/email/event.ex

@@ -15,7 +15,7 @@ defmodule Mobilizon.Web.Email.Event do
   alias Mobilizon.Storage.Repo
   alias Mobilizon.Users.User
 
-  alias Mobilizon.Web.{Gettext, Email}
+  alias Mobilizon.Web.{Email, Gettext}
 
   @important_changes [:title, :begins_on, :ends_on, :status]
 

lib/web/email/participation.ex

@@ -9,9 +9,9 @@ defmodule Mobilizon.Web.Email.Participation do
 
   import Mobilizon.Web.Gettext
 
-  alias Mobilizon.Users.User
   alias Mobilizon.Actors.Actor
   alias Mobilizon.Events.Participant
+  alias Mobilizon.Users.User
 
   alias Mobilizon.Web.{Email, Gettext}
 

lib/web/views/error_view.ex

@@ -49,7 +49,7 @@ defmodule Mobilizon.Web.ErrorView do
     render("500.html", assigns)
   end
 
-  defp index_file_path() do
+  defp index_file_path do
     Path.join(Application.app_dir(:mobilizon, "priv/static"), "index.html")
   end
 end