Add scroll tracking to foreign travel advice pages

[andysellick]

⚠️ This repo is Continuously Deployed: make sure you follow the guidance ⚠️

What

Adds scroll tracking to the pages listed on https://www.gov.uk/foreign-travel-advice (but not that page itself). Should add tracking for all pages for all countries, for example on:

• https://www.gov.uk/foreign-travel-advice/afghanistan
• https://www.gov.uk/foreign-travel-advice/afghanistan/coronavirus
• https://www.gov.uk/foreign-travel-advice/afghanistan/safety-and-security

(etc.)

Uses the new AutoScrollTracker module, initialised as a meta tag, configured to track headings. This is included in the latest version of the gem, which has already been added to government-frontend (this PR rebased to match).

Why

We want to understand user behaviour on these pages in order to improve them.

Visual changes

None.

Trello card: https://trello.com/c/JREgQ2iv/579-spike-into-tracking-enhancements

[kevindew]

Code looks good 👍

I had some trouble testing this out because Static on production doesn't yet contain this file (so ./startup --live didn't work). Thought I'd mention so you don't merge this and find it doesn't work in prod because Static is behind.

[andysellick]

I had some trouble testing this out because Static on production doesn't yet contain this file (so ./startup --live didn't work). Thought I'd mention so you don't merge this and find it doesn't work in prod because Static is behind.

Oh of course 🤦 . I'll make sure static has the new version so you can check it before I merge.

[kevindew]

I had some trouble testing this out because Static on production doesn't yet contain this file (so ./startup --live didn't work). Thought I'd mention so you don't merge this and find it doesn't work in prod because Static is behind.

Oh of course 🤦 . I'll make sure static has the new version so you can check it before I merge.

Thanks, don't worry about me needing to check it though. I used integration yesterday to try it out.