Update karma to 4.2.0 (latest)

Update karma from 3.0.0 to 4.2.0 (latest) and other karma-related packages.

• https://www.npmjs.com/package/karma/v/4.2.0
• https://github.com/karma-runner/karma/releases?after=v4.3.0

BREAKING CHANGES from karma 3.x to 4.x

Drop Support for Node 6, to make it possible to use async/await in karma codebase.

BREAKING CHANGES from karma-jasmine 1.x to 2.x

stopOnFailure, which was previously documented in karma-jasmine's README, is not configuration option for jasmine. Use oneFailurePerSpec instead.

Requires peerDependency Jasmine@^3.3.0

deps: Drop support for node 4.x

cf. #43513 (moved)