make coauthor relation can be edit

app/controllers/desktop/co_author_relations_controller.rb

@@ -8,6 +8,10 @@ class Desktop::CoAuthorRelationsController < ApplicationController
     end
   end
 
+  def edit
+    @co_author_relation = CoAuthorRelation.find(params[:id])
+  end
+
   def new
     @new_relation = CoAuthorRelation.new
   end
@@ -25,6 +29,17 @@ class Desktop::CoAuthorRelationsController < ApplicationController
     end
   end
 
+  def update
+    @co_author_relation = CoAuthorRelation.find(params[:id])
+
+    if @co_author_relation.update_attributes(params[:co_author_relation])
+      render json: {success:true, msg: t('update.sucess.co_author')}.to_json
+    else
+      error_msg = @co_author.errors.full_messages.join("<br />")
+      render json: {success: false, msg: error_msg}.to_json
+    end
+  end
+
   def destroy
     @co_author_relation = CoAuthorRelation.find(params[:id])
     @co_author_relation.destroy