Fixed failing EmailControllerTest
Merge branch 'master' into id-pref-fix
adding schema for books on high relevance component
adding schema to low relevance component
adding schema to medium relevance unit
Read Snapshot S3 Feed in Pre-prod Environments

To avoid hitting rate limit on eventbrite API.
Tag Masterclasses from First Read

Previously after the first read no masterclasses had tags
because the tag lookup happens after the masterclass load.
This change improves that situation by looking up the most common tags
before the first masterclass load so that at least some will be tagged.
adding isbn number to schema
Improve Comparison of Masterclass IDs
Measure Commercial Component Feed Load Times

So we can see how often and for how long they go down
and set sensible timeouts.
only center align ads that need it
Merge pull request #4825 from guardian/ad-align-style

Cnly center align ads that need it
getting the price right
Fixed bug with sort drop down not showing comments
Merge pull request #4818 from guardian/commercial-books-schema

Adding books schema to commercial books components
Merge pull request #4829 from guardian/discussion-sortDropDownBug

Discussion bug fix #4827
ff/opera preroll fixes
Removing social refferer a/b test
Merge pull request #4835 from guardian/remove-test

Removing social referrer a/b test
Removing supporting links a/b test