方法 1：./Scripts/bootstrap.sh -d
方法 2：

1>clear the node and all related files.

2>Install the latest node using homebrew> brew install npm

3>Install the libimobiledevice > brew install libimobiledevice --HEAD

4>Install ios-deploy: npm install -g ios-deploy

5>Install appium 1.7.1 and go to path "/Applications/Appium.app/Contents/Resources/app/node_modules/appium/node_modules/appium-xcuitest-driver/WebDriverAgent"

6>Run command "mkdir -p Resources/WebDriverAgent.bundle"

7>Run command "./Scripts/bootstrap.sh"

All necessary dependancy will get downloaded.