package.json文件配置及其含义，这个是vue-cli自动生成的文件，先贴一张代码及其含义：
{
"name": "secondproject",//模块名称
"version": "1.0.0",//模块版本
"description": "A Vue.js project",//对模块的描述
"author": "datura",//作者是谁
"private": true,//如果值为true,npm将拒绝发布它
"scripts": {//值是一个对象，里面指定了项目的生命周期各个环节需要执行的命令
"dev": "node build/dev-server.js",//这个就是在命令行执行npm run dev,其实是运行dev-server.js文件
"build": "node build/build.js",//build命令（有一个钩子的概念：比如这个build有prebuild和postbuild
"unit": "cross-env BABEL_ENV=test karma start test/unit/karma.conf.js --single-run",//babel是一个编译器，可以把ES6编译成ES5.，这句先是设置编译环境为test环境下；karma是一个运行时，它产生一个web服务环境来运行项目代码，并执行测试。..
"e2e": "node test/e2e/runner.js",//e2e模拟用户行为的测试，端到端测试
"test": "npm run unit && npm run e2e"//执行单元测试和e2e测试
},//关于npm钩子：通常程序只能处理来自内部的消息，如果希望对外部发来的消息也能拦截处理，就需要用到Hook技术。比如想在run build之前自动执行点任务,可以将其写在run prebuild标签里；postbuild在build之后自动执行
"dependencies": {//配置模块依赖的模块列表，key是模块名称，value是版本范围，版本范围是一个字符，可被一个或多个空格分割。
"router": "^1.3.0",//路由版本
"vue": "^2.2.1",//vue版本
"vue-resource": "^1.2.1",//一个插件，通过xmlHttpRequest或jsonp发起请求并处理响应。
"vue-router": "^2.3.0"//
},
"devDependencies": {//这里写的依赖是用于开发环境的，不发布到生产环境。
"autoprefixer": "^6.7.2",
"babel-core": "^6.22.1",
"babel-loader": "^6.2.10",
"babel-plugin-transform-runtime": "^6.22.0",
"babel-preset-latest": "^6.22.0",
"babel-preset-stage-2": "^6.22.0",
"babel-register": "^6.22.0",
"chalk": "^1.1.3",
"connect-history-api-fallback": "^1.3.0",
"copy-webpack-plugin": "^4.0.1",
"css-loader": "^0.26.1",
"eventsource-polyfill": "^0.9.6",
"express": "^4.14.1",
"extract-text-webpack-plugin": "^2.0.0",
"file-loader": "^0.10.0",
"friendly-errors-webpack-plugin": "^1.1.3",
"function-bind": "^1.1.0",
"html-webpack-plugin": "^2.28.0",
"http-proxy-middleware": "^0.17.3",
"webpack-bundle-analyzer": "^2.2.1",
"cross-env": "^3.1.4",
"karma": "^1.4.1",
"karma-coverage": "^1.1.1",
"karma-mocha": "^1.3.0",
"karma-phantomjs-launcher": "^1.0.2",
"karma-sinon-chai": "^1.2.4",
"karma-sourcemap-loader": "^0.3.7",
"karma-spec-reporter": "0.0.26",
"karma-webpack": "^2.0.2",
"lolex": "^1.5.2",
"mocha": "^3.2.0",
"chai": "^3.5.0",
"sinon": "^1.17.7",
"sinon-chai": "^2.8.0",
"inject-loader": "^2.0.1",
"babel-plugin-istanbul": "^3.1.2",
"phantomjs-prebuilt": "^2.1.14",
"chromedriver": "^2.27.2",
"cross-spawn": "^5.0.1",
"nightwatch": "^0.9.12",
"selenium-server": "^3.0.1",
"semver": "^5.3.0",
"opn": "^4.0.2",
"optimize-css-assets-webpack-plugin": "^1.3.0",
"ora": "^1.1.0",
"rimraf": "^2.6.0",
"url-loader": "^0.5.7",
"vue-loader": "^11.0.0",
"vue-style-loader": "^2.0.0",
"vue-template-compiler": "^2.2.1",
"webpack": "^2.2.1",
"webpack-dev-middleware": "^1.10.0",
"webpack-hot-middleware": "^2.16.1",
"webpack-merge": "^2.6.1"
},
"engines": {//指定项目运行的node或者npm版本范围，有点像安卓的指定开发level哦
"node": ">= 4.0.0",
"npm": ">= 3.0.0"
},
"browserlist": [//在不同的前端工具之间共享目标浏览器的库，确定哪些支持哪些版本的浏览器
"> 1%",//全球有超1%的人使用的浏览器
"last 2 versions",//根据CanIUse.com追踪的最后两个版本的所有浏览器
"not ie <= 8"//排除先前查询选择的浏览器 天啦噜 英语不好是硬伤 不知怎么翻译好理解
]
}