- Validated APIVersion fields of the `HorizontalPodAutoscaler` to ensure that API objects were created and functioned properly. ([#132537](https://github.com/kubernetes/kubernetes/pull/132537), [@lalitc375](https://github.com/lalitc375)) [SIG Etcd and Testing]...

##  External Dependencies

- Default etcd server is unchanged at v3.2.24 since Kubernetes 1.12. ([#68318](https://github.com/kubernetes/kubernetes/pull/68318))
- The list of validated docker versions remain unchanged at 1.11.1, 1.12.1, 1.13.1, 17.03, 17.06, 17.09, 18.06 since Kubernetes 1.12. ([#68495](https://github.com/kubernetes/kubernetes/pull/68495))

- Default etcd server and client have been updated to v3.3.10. ([#71615](https://github.com/kubernetes/kubernetes/pull/71615), [#70168](https://github.com/kubernetes/kubernetes/pull/70168))

*   The supported etcd server version is **3.1.10**, as compared to 3.0.17 in v1.8 ([#49393](https://github.com/kubernetes/kubernetes/pull/49393),[ @hongchaodeng](https://github.com/hongchaodeng))
*   The validated docker versions are the same as for v1.8: **1.11.2 to 1.13.1 and 17.03.x**

## External Dependencies
* The supported etcd server version is 3.1.12, as compared to 3.1.10 in v1.9 ([#60998](https://github.com/kubernetes/kubernetes/pull/60998))
* The validated docker versions are the same as for v1.9: 1.11.2 to 1.13.1 and 17.03.x ([ref](https://github.com/kubernetes/kubernetes/blob/release-1.10/test/e2e_node/system/docker_validator_test.go))

    e.g., setting the environment variable `TF_ENABLE_MKL_NATIVE_FORMAT` will
    not have any effect.

*   TensorFlow has been validated on Windows Subsystem for Linux 2 (aka WSL 2)
    for both GPUs and CPUs.

*   Due to security issues (see section below), all boosted trees code has been
    deprecated. Users should switch to