安装报错log如下：
> node install-npm.js
info Chromedriver Install Installing Chromedriver version '2.33' for platform 'mac' and architecture '64'
info Chromedriver Install Opening temp file to write chromedriver_mac64 to...
info Chromedriver Install Downloading https://chromedriver.storage.googleapis.com/2.33/chromedriver_mac64.zip...
RequestError: Error: connect ETIMEDOUT 172.217.160.112:443
at new RequestError (/Users/09/Downloads/appium-1.7.2/node_modules/request-promise/lib/errors.js:11:15)
at Request.RP$callback [as _callback] (/Users/09/Downloads/appium-1.7.2/node_modules/request-promise/lib/rp.js:60:32)
at self.callback (/Users/09/Downloads/appium-1.7.2/node_modules/request/request.js:186:22)
at Request.emit (events.js:159:13)
at Request.onRequestError (/Users/09/Downloads/appium-1.7.2/node_modules/request/request.js:878:8)
at ClientRequest.emit (events.js:159:13)
at TLSSocket.socketErrorListener (_http_client.js:389:9)
at TLSSocket.emit (events.js:159:13)
at emitErrorNT (internal/streams/destroy.js:64:8)
at process._tickCallback (internal/process/next_tick.js:152:19)
npm ERR! code ELIFECYCLE
npm ERR! errno 1
npm ERR! appium-chromedriver@3.1.4 install: `node install-npm.js`
npm ERR! Exit status 1
npm ERR!
npm ERR! Failed at the appium-chromedriver@3.1.4 install script.
npm ERR! This is probably not a problem with npm. There is likely additional logging output above.
npm ERR! A complete log of this run can be found in:
npm ERR! /Users/09/.npm/_logs/2018-01-09T05_59_22_922Z-debug.log
解决办法，去appium官网下载源码
解压文件在目录：node_modules文件夹中增加appium-chromedriver目录
将log中的地址文件：https://chromedriver.storage.googleapis.com/2.33/chromedriver_mac64.zip
下载，将解压后的内容放到刚创建的目录中，之后从终端进入源码目录，执行npm install
即可。
