Try to fix CI build
Remove dependency on govuk_setenv

We're probably not going to use this on the CI boxes, so we should just
set the desired environment variables explicitly.
Make parent container of link open with popup

In order to make the link that fired the popup visible the parent tabbed
panel needs to show.

Also includes a fix for the arrows on expanding lists not displaying
correctly in IE.
Merge branch 'master' of github.com:alphagov/trade-tariff-frontend into enable-lightbox-in-new-tab
Merge branch 'enable-lightbox-in-new-tab' of github.com:alphagov/trade-tariff-frontend into enable-lightbox-in-new-tab