Fix creating document creator not being contributor

When using the nuxeo-web-ui-ftest framework, when provisioning, the created documents are being created by a chosen user but the contributor is still Administrator. The creator of a document should also be a contributor.

Example in step used in search.feature

• search.js

  Given(/^I have the following documents$/, (table) => {
    browser.pause(1000);
    const tasks = table.rows().map(row => () => {
      const doc = fixtures.documents.init(row[0]);
      doc.name = row[1];
      doc.properties = {
        'dc:title': row[1],
        'dc:nature': row[2],
        'dc:subjects': [row[3]],
        'dc:coverage': row[4],
      };
      if (row[0] === 'Note') {
        doc.properties = {
          'dc:title': row[1],
          'dc:nature': row[2],
          'dc:subjects': [row[3]],
          'dc:coverage': row[4],
          'note:note': 'Lorem Ipsum',
        };
      }
      // create the document
      return fixtures.documents.createWithAuthor(row[6], doc, row[5]).then((docWithAuthor) => {
        if (row[7].length > 0) {
          return fixtures.collections.addToCollection(docWithAuthor, row[7]).then((docInCollection) => {
            if (row[8].length > 0) {
              return fixtures.documents.addTag(docInCollection, row[8]).then((docWithTag) => {
                if (row[9].length > 0) {
                  return fixtures.documents.attach(docWithTag, fixtures.blobs.get(row[9]));
                }
              });
            }
          });
        }
      });
    });
    return tasks.reduce((current, next) => current.then(next), Promise.resolve([]));
  });
  

• document.js:

createWithAuthor: (parent, document, username) => nuxeo.repository()
    .create(parent, document)
    .then((doc) => {
      liveDocuments.push(doc.uid);
      if (username) {
        return doc.set({
          'dc:creator': username,
        }).save();
      }
      return doc;
    }),