Support Node >= 10 in 5.0.2

[codymikol]

since 5.0.1 was a hotfix release, we should not have changed the node target, I will see if we can support Node >= 10 in a hotfix release for 5.0.2 and then change the target for 6.0.0.

[alexander-akait]

@codymikol Feel free to fix it and make a release, I added you https://www.npmjs.com/package/karma-webpack/ and now you have write access, so feel free to make releases when you want