Merge pull request #18833 from apple/readme-add-tf-gpu

[README] Add TensorFlow GPU CI platform
diff --git a/README.md b/README.md
index 6df9a38..be93510 100644
--- a/README.md
+++ b/README.md
@@ -22,6 +22,7 @@
 |**[Ubuntu 16.04 ](https://github.com/apple/swift-community-hosted-continuous-integration/blob/master/nodes/aarch64_ubuntu_16.04.json)** | AArch64 |[![Build Status](https://ci-external.swift.org/job/oss-swift-RA-linux-ubuntu-16.04-aarch64/lastCompletedBuild/badge/icon)](https://ci-external.swift.org/job/oss-swift-RA-linux-ubuntu-16.04-aarch64)|
 |**[Ubuntu 16.04 (Android)](https://github.com/apple/swift-community-hosted-continuous-integration/blob/master/nodes/x86_64_ubuntu_16_04_LTS_android.json)** | x86_64 |[![Build Status](https://ci-external.swift.org/job/oss-swift-RA-linux-ubuntu-16.04-android/lastCompletedBuild/badge/icon)](https://ci-external.swift.org/job/oss-swift-RA-linux-ubuntu-16.04-android)|
 |**[macOS 10.13 (TensorFlow)](https://github.com/apple/swift-community-hosted-continuous-integration/blob/master/nodes/x86_64_macos_high_sierra_tensorflow.json)** | x86_64 |[![Build Status](https://ci-external.swift.org/job/oss-swift-RA-macOS-tensorflow/lastCompletedBuild/badge/icon)](https://ci-external.swift.org/job/oss-swift-RA-macOS-tensorflow)|
+|**[Ubuntu 16.04 (TensorFlow with GPU)](https://github.com/apple/swift-community-hosted-continuous-integration/blob/master/nodes/x86_64_ubuntu_16_04_tensorflow_gpu.json)** | x86_64 |[![Build Status](https://ci-external.swift.org/job/oss-swift-RA-linux-ubuntu-16.04-tensorflow-gpu/lastCompletedBuild/badge/icon)](https://ci-external.swift.org/job/oss-swift-RA-linux-ubuntu-16.04-tensorflow-gpu)|
 
 
 **Welcome to Swift!**