Attachments are now scanned for suitable featured image when post is initially parsed
Moved featured image parsing to one place at end of post parsing
Check featured_media first
Changed min featured image width to 600px to match the iOS app
Changed min featured image width to 640px after discussion - https://github.com/wordpress-mobile/WordPress-iOS/issues/2922
Merge pull request #2101 from wordpress-mobile/issue/2100-reader-attachments

issue/2100-reader-attachments
Merge branch 'develop' of https://github.com/wordpress-mobile/WordPress-Android into feature/reader-material-tweaks