Ignore bundle.js in benchmark tools (#1162)
Ignore bundle.js in benchmark tools (#1162)

Benchmark tools generate `bundle.js` which includes whole dependencies to be runnable in a browser. Since it's generated from TypeScript source code, we can remove it from version control.
tensorflow/tfjs,tensorflow/tfjs,tensorflow/tfjs,tensorflow/tfjs-core,tensorflow/tfjs-core,tensorflow/tfjs-core,tensorflow/tfjs,tensorflow/tfjs-core,tensorflow/tfjs-core,tensorflow/tfjs,tensorflow/tfjs,tensorflow/tfjs,tensorflow/tfjs,tensorflow/tfjs-core,tensorflow/tfjs