Fix history pagination with paper_trail, specs

[vlobanov]

Hi!
When using PaperTrail extension, RailsAdmin::Extensions::PaperTrail::AuditingAdapter was returning VersionProxy objects array:

versions.collect { |version| VersionProxy.new(version, @user_class) }

which is later used in history view:

- unless params[:all] || [email protected]_to?(:current_page)

The array returned by collect obviously doesn't respond to #current_page, as a result history pages have no pagination. Fix, and PaperTrail integration specs

[kirillplatonov]

👍

[mshibuya]

Looks nice, thanks!