constness

src/docker.js

@@ -117,7 +117,7 @@ async function pullImage(manifest) {
         // https://github.com/dotcloud/docker/issues/1074 says each status message
         // is emitted as a chunk
         stream.on('data', function (chunk) {
-            var data = safe.JSON.parse(chunk) || { };
+            const data = safe.JSON.parse(chunk) || { };
             debug('pullImage: %j', data);
 
             // The data.status here is useless because this is per layer as opposed to per image