Update karma to the latest version 🚀

The devDependency karma was updated from `3.1.4` to `4.0.1`.

This version is not covered by your current version range.

If you don’t accept this pull request, your project will work just like it did before. However, you might be missing out on a bunch of new features, fixes and/or performance improvements from the dependency update.

Release Notes for v4.0.1

Bug Fixes

browser: allow updating total specs count (#3264) (d5df723)
remove vulnerable dependency combine-lists (#3273) (c43f584), closes #3265
remove vulnerable dependency expand-braces (#3270) (4ec4f6f), closes #3268 #3269
filelist: correct logger name. (#3262) (375bb5e)
launcher: Debug Child Processes exit signal (#3259) (c277a6b)

Commits

The new version differs by 20 commits.

c7ebf0b chore: release v4.0.1
c190c4a chore: update contributors
375bb5e fix(filelist): correct logger name. (#3262)
c43f584 fix: remove vulnerable dependency combine-lists (#3273)
4ec4f6f fix: remove vulnerable dependency expand-braces (#3270)
d5df723 fix(browser): allow updating total specs count (#3264)
c277a6b fix(launcher): Debug Child Processes exit signal (#3259)
bd95d89 chore: upgrade log4js to v4.0.0 (#3257)
5a47718 chore: release v4.0.0
56cc239 chore: update contributors
d59cf35 refactor(watcher): Make watcher injectable to support 3rd-party watchers (#3254)
988b901 chore(license): Update copyright notice to 2019 [ci skip] (#3250)
571191c fix(client): fix issue with loaded on safari 10 (#3252)
376142e refactor(fileList): refactor with async/await (#3247)
acdd2dc refactor(server): refactor start method to use async/await (#3245)

There are 20 commits in total.

See the full diff

FAQ and help

There is a collection of [frequently asked questions](https://greenkeeper.io/faq.html). If those don’t help, you can always [ask the humans behind Greenkeeper](https://github.com/greenkeeperio/greenkeeper/issues/new).

Your Greenkeeper bot :palm_tree:

videojs / mpd-parser