Fix invalid param to fetch api (tensorflow#58)

Author: tafsiri

mnist-core/data.js

@@ -84,7 +84,7 @@ export class MnistData {
       img.src = MNIST_IMAGES_SPRITE_PATH;
     });
 
-    const labelsRequest = fetch(MNIST_LABELS_PATH, {mode: 'arraybuffer'});
+    const labelsRequest = fetch(MNIST_LABELS_PATH);
     const [imgResponse, labelsResponse] =
         await Promise.all([imgRequest, labelsRequest]);
 

mnist/data.js

@@ -82,7 +82,7 @@ export class MnistData {
       img.src = MNIST_IMAGES_SPRITE_PATH;
     });
 
-    const labelsRequest = fetch(MNIST_LABELS_PATH, {mode: 'arraybuffer'});
+    const labelsRequest = fetch(MNIST_LABELS_PATH);
     const [imgResponse, labelsResponse] =
         await Promise.all([imgRequest, labelsRequest]);