adding schema for books on high relevance component
adding schema to low relevance component
adding schema to medium relevance unit
adding isbn number to schema
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
Merge branch 'master' into vip-tests