update installation doc and Homebrew to use 1.0.0-beta.8 (#2578)

Author: Mengqi Yu

Formula/kpt.rb

@@ -15,8 +15,8 @@
 class Kpt < Formula
   desc "Toolkit to manage,and apply Kubernetes Resource config data files"
   homepage "https://googlecontainertools.github.io/kpt"
-  url "https://github.com/GoogleContainerTools/kpt/archive/v1.0.0-beta.7.tar.gz"
-  sha256 "e31e7ee63006150f730ed8a08e9063a2fb2faf9e617353e3649ef893bdf7c156"
+  url "https://github.com/GoogleContainerTools/kpt/archive/v1.0.0-beta.8.tar.gz"
+  sha256 "acee77648eda421f4b89041ec63c7170a31ba68070e159d5ad475e80d31284dc"
 
   depends_on "go" => :build
 

site/installation/README.md

@@ -70,15 +70,15 @@ Use one of the kpt docker images.
 ### `kpt`
 
 ```shell
-$ docker run gcr.io/kpt-dev/kpt:v1.0.0-beta.7 version
+$ docker run gcr.io/kpt-dev/kpt:v1.0.0-beta.8 version
 ```
 
 ### `kpt-gcloud`
 
 An image which includes kpt based upon the Google [cloud-sdk] alpine image.
 
 ```shell
-$ docker run gcr.io/kpt-dev/kpt-gcloud:v1.0.0-beta.7 version
+$ docker run gcr.io/kpt-dev/kpt-gcloud:v1.0.0-beta.8 version
 ```
 
 ## Source
@@ -101,7 +101,7 @@ $ kpt version
   https://console.cloud.google.com/gcr/images/kpt-dev/GLOBAL/kpt-gcloud?gcrImageListsize=30
 [cloud-sdk]: https://github.com/GoogleCloudPlatform/cloud-sdk-docker
 [linux]:
-  https://github.com/GoogleContainerTools/kpt/releases/download/v1.0.0-beta.7/kpt_linux_amd64
+  https://github.com/GoogleContainerTools/kpt/releases/download/v1.0.0-beta.8/kpt_linux_amd64
 [darwin]:
-  https://github.com/GoogleContainerTools/kpt/releases/download/v1.0.0-beta.7/kpt_darwin_amd64
+  https://github.com/GoogleContainerTools/kpt/releases/download/v1.0.0-beta.8/kpt_darwin_amd64
 [migration guide]: /installation/migration