Fix response output for Detect Labels (#199)

Before, this was dumping an object via console.log
Now, this properly prints just the label description

Author: beccasaurus

vision/samples/detect.js

@@ -102,7 +102,7 @@ function detectLabels(fileName) {
     .then(results => {
       const labels = results[0].labelAnnotations;
       console.log('Labels:');
-      labels.forEach(label => console.log(label));
+      labels.forEach(label => console.log(label.description));
     })
     .catch(err => {
       console.error('ERROR:', err);
@@ -130,7 +130,7 @@ function detectLabelsGCS(bucketName, fileName) {
     .then(results => {
       const labels = results[0].labelAnnotations;
       console.log('Labels:');
-      labels.forEach(label => console.log(label));
+      labels.forEach(label => console.log(label.description));
     })
     .catch(err => {
       console.error('ERROR:', err);