Adds cancel button to edit book page

bookwyrm/templates/book.html

@@ -11,7 +11,7 @@
 
         {% if request.user.is_authenticated and perms.bookwyrm.edit_book %}
         <div class="level-right">
-            <a href="{{ book.id }}/edit">edit
+            <a href="{{ book.id }}/edit">
                 <span class="icon icon-pencil">
                     <span class="is-sr-only">Edit Book</span>
                 </span>

bookwyrm/templates/edit_book.html

@@ -78,6 +78,7 @@
     </div>
     <div class="block">
         <button class="button is-primary" type="submit">Save</button>
+        <a class="button is-danger is-light" href="/book/{{ book.id }}">Cancel</a>
     </div>
 </form>