Update dependency webpack-dev-server to v3.4.1

[renovate[bot]]

This PR contains the following updates:

Package	Type	Update	Change	References
webpack-dev-server	devDependencies	minor	3.3.1 -> 3.4.1	source

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Release Notes

webpack/webpack-dev-server

### [`v3.4.1`](https://togithub.com/webpack/webpack-dev-server/blob/master/CHANGELOG.md#​341httpsgithubcomwebpackwebpack-dev-servercomparev340v341-2019-05-17) [Compare Source](https://togithub.com/webpack/webpack-dev-server/compare/v3.4.0...v3.4.1) ### [`v3.4.0`](https://togithub.com/webpack/webpack-dev-server/blob/master/CHANGELOG.md#​340httpsgithubcomwebpackwebpack-dev-servercomparev331v340-2019-05-17) [Compare Source](https://togithub.com/webpack/webpack-dev-server/compare/v3.3.1...v3.4.0) ##### Bug Fixes - don't use self.location.port ([#​1838](https://togithub.com/webpack/webpack-dev-server/issues/1838)) ([6d31984](https://togithub.com/webpack/webpack-dev-server/commit/6d31984)) - do not include config files in dist ([#​1883](https://togithub.com/webpack/webpack-dev-server/issues/1883)) ([c535bb2](https://togithub.com/webpack/webpack-dev-server/commit/c535bb2)) - only add client entry to web targets ([#​1775](https://togithub.com/webpack/webpack-dev-server/issues/1775)) ([cf4d0d0](https://togithub.com/webpack/webpack-dev-server/commit/cf4d0d0)) - update clientLogLevel to match docs and error ([#​1825](https://togithub.com/webpack/webpack-dev-server/issues/1825)) ([7f52bbf](https://togithub.com/webpack/webpack-dev-server/commit/7f52bbf)) - add errors-warnings preset ([#​1895](https://togithub.com/webpack/webpack-dev-server/issues/1895)) ([2a81ad2](https://togithub.com/webpack/webpack-dev-server/commit/2a81ad2)) ##### Features - added injectClient option ([#​1775](https://togithub.com/webpack/webpack-dev-server/issues/1775)) ([cf4d0d0](https://togithub.com/webpack/webpack-dev-server/commit/cf4d0d0)) - added injectHot option ([#​1775](https://togithub.com/webpack/webpack-dev-server/issues/1775)) ([cf4d0d0](https://togithub.com/webpack/webpack-dev-server/commit/cf4d0d0)) - added sockPort option ([#​1792](https://togithub.com/webpack/webpack-dev-server/issues/1792)) ([58d1682](https://togithub.com/webpack/webpack-dev-server/commit/58d1682)) - added sockHost option ([#​1858](https://togithub.com/webpack/webpack-dev-server/issues/1858)) ([f47dff2](https://togithub.com/webpack/webpack-dev-server/commit/f47dff2)) - support HEAD method ([#​1875](https://togithub.com/webpack/webpack-dev-server/issues/1875)) ([c2360e4](https://togithub.com/webpack/webpack-dev-server/commit/c2360e4)) - added liveReload option ([#​1889](https://togithub.com/webpack/webpack-dev-server/issues/1889)) ([fc4fe32](https://togithub.com/webpack/webpack-dev-server/commit/fc4fe32)) - update express to 4.17 version

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