anchor.diff:  They can include news articles or govermental websites, 
   but also youtube video and other online sources.
   
  -## Source [/sources/{id}]
  +## Source [/sources/{id}{?include}]
   
   + Parameters
       + id: 1 (required, string) - ID of the source; TODO shouldn't we use URIs?
  
positive.code: + Response 200 (application/json)
      + Attributes (Statement)
  
  ## Statements list [/statements{?uri}]
  
  ### Statements in given source [GET]
  
  This endpoint will return all the statements that are associated with
  the specified `uri`. If no `uri` parameter is set all the statements 
  in the database will be returned.
  
  + Parameters
      + uri (optional, URI, `http://www.agerpres.ro/politica/2016/07/10/dragnea-de-cand-e-gabriela-firea-primar-nu-s-a-taiat-niciun-pom-pe-kiseleff-21-41-07`) ... URI to check for a fact check.
  
  + Response 200 (application/json)
      + Attributes
  
negative.code: 
  + Response 200 (application/json)
      + Attributes (Source)
  
  ### View a source with statements [GET /sources/{id}{?include}]
  
  + Parameters
      + id: 1 (required, string) - ID of the source; TODO shouldn't we use URIs?
      + include: statements (string, optional) - include statements from this URI
  
  + Response 200 (application/json)
      + Attributes (Source)
          + included (array[Statement Object])
  
  ## Sources list [/sources]
  
  