环境：

Ubuntu 18 (WSL)
Tensorflow=1.1.0
python=2.7
global modules path = /home/linuxbrew/.linuxbrew/lib
appium = 1.19.1
node = 15.4.0
npm=6.14.9
test-ai-classifier=4.0.2

先决条件：

Install Android SDK and configure ANDROID_HOME 
Install Java SDK and configure JAVA_HOME

安装步骤：

sudo apt-get update
sudo apt-get install build-essential \
curl git m4 ruby texinfo libbz2-dev \
libcurl4-openssl-dev libexpat-dev libncurses-dev zlib1g-dev

rm -rf /home/linuxbrew/.linuxbrew/lib/node_modules
brew uninstall node
cd ~/
sudo rm -rf /home/linuxbrew
sh -c "$(curl -fsSL https://raw.githubusercontent.com/Linuxbrew/install/master/install.sh)"

# Add this to end of bashrc

sudo nano ~/.bashrc
export PATH="/home/linuxbrew/.linuxbrew/bin:$PATH"
export MANPATH="/home/linuxbrew/.linuxbrew/share/man:$MANPATH"
export INFOPATH="/home/linuxbrew/.linuxbrew/share/info:$INFOPATH"

# Source bashrc

source ~.bashrc

brew install gcc
brew update
brew install node
brew link node
npm i -g npm@latest

npm install -g appium --drivers=xuitest,uiautomator2
npm install -g wd
sudo lsof -i :4723 or (ps aux | grep node)
sudo kill -9 PID
appium
sudo rm -rf ~/.appium
npm install -g appium-doctor
appium-doctor

sudo apt-get install pkg-config libcairo2-dev libpango* libpng-dev libjpeg-dev giflib*
npm install -g node-pre-gyp@0.11.0
npm install --unsafe-perm --verbose -g node-sass
npm install -g node-gyp --unsafe-perm=true
NODE_GYP_FORCE_PYTHON=python
NODE_GYP_FORCE_PYTHON=python2
sudo update-alternatives --install /usr/bin/python python /usr/bin/python2.7 10
sudo apt-get install libgif-dev    
npm install -g test-ai-classifier

安装时显示以下错误test-ai-classifier@4.0.2:

Will download object detection model from remote host
Checking whether /home/linuxbrew/.linuxbrew/lib/node_modules/test-ai-classifier/model/obj_detection_model exists...
Downloading model from https://data.test.ai/appium-plugin/object-detection-model.pb...
RequestError: Error: certificate has expired
    at new RequestError (/home/linuxbrew/.linuxbrew/lib/node_modules/test-ai-classifier/node_modules/request-promise-core/lib/errors.js:14:15)
    at Request.plumbing.callback (/home/linuxbrew/.linuxbrew/lib/node_modules/test-ai-classifier/node_modules/request-promise-core/lib/plumbing.js:87:29)
    at Request.RP$callback [as _callback] (/home/linuxbrew/.linuxbrew/lib/node_modules/test-ai-classifier/node_modules/request-promise-core/lib/plumbing.js:46:31)
    at self.callback (/home/linuxbrew/.linuxbrew/lib/node_modules/test-ai-classifier/node_modules/request/request.js:185:22)
    at Request.emit (node:events:376:20)
    at Request.onRequestError (/home/linuxbrew/.linuxbrew/lib/node_modules/test-ai-classifier/node_modules/request/request.js:877:8)
    at ClientRequest.emit (node:events:376:20)
    at TLSSocket.socketErrorListener (node:_http_client:486:9)
    at TLSSocket.emit (node:events:376:20)
    at emitErrorNT (node:internal/streams/destroy:188:8)
    at emitErrorCloseNT (node:internal/streams/destroy:153:3)
    at processTicksAndRejections (node:internal/process/task_queues:80:21)
WARN: Download of object detection model failed. Object detection mode will not work.
+ test-ai-classifier@4.0.2
added 468 packages from 481 contributors in 1676.706s

问题：
为什么发生“证书已过期”错误时test-ai-classifier@4.0.2 是否已安装？
为什么目标检测模型下载失败？
是否需要安装Python3.8test-ai-classifier@4.0.2?
是否需要安装tensorflow 2.3版test-ai-classifier@4.0.2?
注意：test ai classifier 2.1.1版成功，如下链接所示：如何使用appium for ui selectors正确安装test ai classifier插件？