Refs issue #14: Add the updating functionality

app/controllers/authors_controller.rb

@@ -25,6 +25,16 @@ def create
     end
   end
 
+  def update
+    @author = Author.find(params[:id])
+
+    if @author.update(author_params)
+      redirect_to @author
+    else
+      render 'edit'
+    end
+  end
+
   private
   def author_params
     params.require(:author).permit(:first_name, :last_name, :homepage)