Official Devise Lockable Docs:
https://github.com/heartcombo/devise/wiki/How-To:-Add-:lockable-to-Users

devise lockable if password wrong 3 times
https://github.com/corsego/40-devise-everything/commit/e72151d4c57043a0607b5bb558748ad9621539b4
ban or unban users
https://github.com/corsego/40-devise-everything/commit/ce1bd0ee4567a0a2f08238da1402bfda4dfd96bc