Book detail get author using get_absolute_url (mdn#91)

Author: hamishwillee

catalog/templates/catalog/book_detail.html

@@ -4,7 +4,7 @@
 
 <h1>Title: {{ book.title }}</h1>
 
-<p><strong>Author:</strong> <a href="{% url 'author-detail' book.author.pk %}">{{ book.author }}</a></p>
+<p><strong>Author:</strong> <a href="{{ book.author.get_absolute_url }}">{{ book.author }}</a></p>
 <p><strong>Summary:</strong> {{ book.summary }}</p>
 <p><strong>ISBN:</strong> {{ book.isbn }}</p> 
 <p><strong>Language:</strong> {{ book.language }}</p>