create api to get and add Content
Improve POST service to '/api/add/content' to return error due missing data
Create a temporal 'temp' folder to store temporal files'
Add Test cases for rest_service 'add folder and images'
Error status is returned when user try to add a duplicated element
Merge pull request #2 from ariel-cossio/rest_services/add_folder_and_images

Rest services/add folder and images