Update webpack-dev-server to version 2.4.0 🚀

[greenkeeperio-bot]

Hello lovely humans,

webpack-dev-server just published its new version 2.4.0.

State	Update 🚀
Dependency	webpack-dev-server
New version	2.4.0
Type	devDependency

This version is not covered by your current version range.

Without accepting this pull request your project will work just like it did before. There might be a bunch of new features, fixes and perf improvements that the maintainers worked on for you though.

I recommend you look into these changes and try to get onto the latest version of webpack-dev-server.
Given that you have a decent test suite, a passing build is a strong indicator that you can take advantage of these changes by merging the proposed change into your project. Otherwise this branch is a great starting point for you to work on the update.

Do you have any ideas how I could improve these pull requests? Did I report anything you think isn’t right?
Are you unsure about how things are supposed to work?

There is a collection of frequently asked questions and while I’m just a bot, there is a group of people who are happy to teach me new things. Let them know.

Good luck with your project ✨

You rock!

🌴

---

The new version differs by 238 commits (ahead by 238, behind by 34).

• 3f7c9f7 2.4.0
• e22317f Setting contentBase to false with historyApiFallback on works properly #791 (#797)
• b85a0ce Extract logic of adding entry points (#782)
• 4991704 feat - Allow overlay to be enabled for warnings (#789) (#790)
• 9d2925c Update dependencies
• 0099613 Handle promise rejection when using --open flag (#780)
• 04eafa5 2.3.0
• ac1675c Refactor config validation
• d725fd9 Implement error overlay (#764)
• 61e5403 Allow a string to be passed as the port config option (#766)
• 2cf2939 have --open use the options.public path if it exists (#749)
• aa98997 2.2.1
• 686dec4 Fix inline example not working after webpack 2.2.0
• c82c1eb Only run Travis on the master branch [skip ci]
• 54b4b02 update examples to reflect web pack 2.2.0 (#759)

There are 238 commits in total. See the full diff.

---

✨ Try the all new Greenkeeper GitHub Integration ✨
With Integrations first-class bot support landed on GitHub and we’ve rewritten Greenkeeper to take full advantage of it. Simpler setup, fewer pull-requests, faster than ever. Screencast Try it today. Free for private repositories during beta.

[coveralls]

Coverage remained the same at 89.0% when pulling 85adb3a on greenkeeper-webpack-dev-server-2.4.0 into 020295b on master.

[instantlinux]

replaced by #447