Support for rails 5, fix undefined method `attr_accessible' error

[andrefy]

Rails 5 active record deprecate the use of attr_accessible,

[anke1460]

Maybe you can add gem 'protected_attributes'?

[andrefy]

'protected_attributes' does not work with rails5 active record

[kostyantyn]

Thanks for opening an issue. @andrefy @anke1460 do you think you can and have enough time to contribute to this gem? I'm looking for a person who I can give admin permissions to this project.