Allow use getDocuments method to find just one document

[danielcastill0]

Hey guys, since release of Truevault API V2, it doesn't needed to do the next validation for search document ` if (documentIds.length === 1) {

                                // Sending a single ID to the API will only return the document's contents. In order to
                                // retrieve a proper multiget response with `id` and `owner_id`, we need to send a
                                // request with two instances of the same document ID. We will then only return the
                                // first result from the response.
                                requestDocumentIds = [documentIds[0], documentIds[0]];
                            } else {
                                requestDocumentIds = documentIds;
                            }`  instead you can just code `requestDocumentIds = documentIds;` and it shoud work perfectly