Add endpoint to update an Article

[bartaelterman]

The user needs to be able to update Articles in the webapp database. After running a classification in Matlab, the resulting epu_score for each Article should be written to the webapp. I think it's best to use the REST interface for this. However, this endpoint should only be accessible after authentication. Preferably, a user can update Articles in batch.

Something like this:

• A user sends a POST request to the server, including the following JSON data:

{
    "articles":
        [
            {"23": {"epu_score": 0.342}},
            {"41": {"epu_score": 0.2148}},
            {"55": {"epu_score": 0.832}}
        ]
}

• Every key in the articles array corresponds to a primary key of the Articles in the webapp database. The JSON objects for each article have the form field: new_value and in this case, only the epu_score is updated for three Articles: 23, 41 and 55.