Add PUT method to the /lists webservice to update the description

[danielabutano]

Added the PUT http method to the existing /lists web service. It receives in input 2 string parameters passed in the URL: name (name of the list belonging to the user) and newDescription
Return status code 400 for missing parameters or wrong list name

[heralden]

I just noticed that if newDescription is set to an empty string, the backend will return "Missing parameter: 'newDescription'". We should be able to remove the description by setting it to an empty string.

[danielabutano]

@uosl try again.It should be fixed now

[heralden]

@danielabutano Would it be possible to allow users whom are not logged in to add a description to their list? Right now it will respond with success, but the description for the list will still be null.