安装webpack-dev-server后，npm run dev报错

> vuewebpack@1.0.0 dev F:GitHubvuevueWebpack
> cross-env NODE_ENV=development webpack-dev-server --config webpack.config.js

F:GitHubvuevueWebpack ode_modulesajv-keywordskeywordsinstanceof.js:52
throw new Error('invalid "instanceof" keyword value ' + c);
^

Error: invalid "instanceof" keyword value Promise
at getConstructor (F:GitHubvuevueWebpack ode_modulesajv-keywordskeywordsinstanceof.js:52:11)
at Ajv.compile (F:GitHubvuevueWebpack ode_modulesajv-keywordskeywordsinstanceof.js:21:27)
at Object.useCustomRule (F:GitHubvuevueWebpack ode_modulesajvlibcompileindex.js:275:26)
at Object.generate_custom [as code] (F:GitHubvuevueWebpack ode_modulesajvlibdotjscustom.js:32:24)
at Object.generate_validate [as validate] (F:GitHubvuevueWebpack ode_modulesajvlibdotjsvalidate.js:347:35)
at Object.generate_anyOf [as code] (F:GitHubvuevueWebpack ode_modulesajvlibdotjsanyOf.js:34:27)
at generate_validate (F:GitHubvuevueWebpack ode_modulesajvlibdotjsvalidate.js:347:35)
at localCompile (F:GitHubvuevueWebpack ode_modulesajvlibcompileindex.js:87:22)
at Ajv.compile (F:GitHubvuevueWebpack ode_modulesajvlibcompileindex.js:56:13)
at Ajv._compile (F:GitHubvuevueWebpack ode_modulesajvlibajv.js:358:27)
npm ERR! code ELIFECYCLE
npm ERR! errno 1
npm ERR! vuewebpack@1.0.0 dev: `cross-env NODE_ENV=development webpack-dev-server --config webpack.config.js`
npm ERR! Exit status 1
npm ERR!
npm ERR! Failed at the vuewebpack@1.0.0 dev 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! C:UsersAdministratorAppDataRoaming pm-cache\_logs2018-06-11T14_03_14_218Z-debug.log

解决：版本的影响