message: Fix the GCS Kokoro build badge links.
  The original badges I added were redirected/authenticated links (I think). This
  resulted in broken images on the README. These new links should not be
  redirected and should just link to the badge images.
diff: | **`Documentation`** | **`Linux CPU`** | **`Linux GPU`** | **`Mac OS CPU`** | **`Windows CPU`** | **`Android`** |
  |-----------------|---------------------|------------------|-------------------|---------------|---------------|
  -| [![Documentation](https://img.shields.io/badge/api-reference-blue.svg)](https://www.tensorflow.org/api_docs/) | ![Build Status](https://storage.cloud.google.com/tensorflow-kokoro-build-badges/ubuntu-cc.png) | ![Build Status](https://storage.cloud.google.com/tensorflow-kokoro-build-badges/ubuntu-gpu-cc.png) | ![Build Status](https://storage.cloud.google.com/tensorflow-kokoro-build-badges/macos-py2-cc.png) | [![Build Status](https://ci.tensorflow.org/buildStatus/icon?job=tensorflow-master-win-cmake-py)](https://ci.tensorflow.org/job/tensorflow-master-win-cmake-py) | [![Build Status](https://ci.tensorflow.org/buildStatus/icon?job=tensorflow-master-android)](https://ci.tensorflow.org/job/tensorflow-master-android) [ ![Download](https://api.bintray.com/packages/google/tensorflow/tensorflow/images/download.svg) ](https://bintray.com/google/tensorflow/tensorflow/_latestVersion)
  +| [![Documentation](https://img.shields.io/badge/api-reference-blue.svg)](https://www.tensorflow.org/api_docs/) | ![Build Status](https://storage.googleapis.com/tensorflow-kokoro-build-badges/ubuntu-cc.png) | ![Build Status](https://storage.googleapis.com/tensorflow-kokoro-build-badges/ubuntu-gpu-cc.png) | ![Build Status](https://storage.googleapis.com/tensorflow-kokoro-build-badges/macos-py2-cc.png) | [![Build Status](https://ci.tensorflow.org/buildStatus/icon?job=tensorflow-master-win-cmake-py)](https://ci.tensorflow.org/job/tensorflow-master-win-cmake-py) | [![Build Status](https://ci.tensorflow.org/buildStatus/icon?job=tensorflow-master-android)](https://ci.tensorflow.org/job/tensorflow-master-android) [ ![Download](https://api.bintray.com/packages/google/tensorflow/tensorflow/images/download.svg) ](https://bintray.com/google/tensorflow/tensorflow/_latestVersion)
  **TensorFlow** is an open source software library for numerical computation using
  data flow graphs. The graph nodes represent mathematical operations, while
  