configure papertrail
Add views for versions
Versions view
Delete table
Edit views and add button in moderator cabinet
inherit from AdminController
modify seeds file
articles search
exhibits search
add exhibitions search
add exhibitions search
ajaxify exhibition search
set columns for date filters
add specs
10 results per page for articles search
Merge pull request #28 from SoftServeUniversity/context_search

Context search
merge master
remove versions_controller_spec.rb
it works, Yeahh
configure PaperTrail for using in specs