Machaba: Refactored Edit function in Book Controller + test
Machaba: If book cover image cannot be loaded, then display the default cover image - fix for books on the home page
Merge branch 'master' of https://github.com/ThoughtWorksZA/bookworm
Machaba: Fixed default image styling on chrome
Merge branch 'master' of https://github.com/ThoughtWorksZA/bookworm