Require alchemy/version in controllers using ssl_required

We need to `require "alchemy/version"` in these controllers to
be able to read the `Alchemy.gem_version`. This file is not
required anywhere and the method will not be defined otherwise.

Closes #111

Author: tvdeyen

app/controllers/alchemy/admin/passwords_controller.rb

@@ -1,3 +1,7 @@
+# frozen_string_literal: true
+
+require "alchemy/version"
+
 module Alchemy
   module Admin
     class PasswordsController < ::Devise::PasswordsController

app/controllers/alchemy/admin/user_sessions_controller.rb

@@ -1,6 +1,6 @@
 # frozen_string_literal: true
 
-require_dependency "alchemy/version"
+require "alchemy/version"
 
 module Alchemy
   module Admin