Versions

just using ng update @angular/cli to upgrade from angular-cli 1.x to 6

Repro steps

• Step - ng update @angular/cli, then check the migrated file karma.conf.js

Observed behavior

the old property 'angularCli' still exists in the new file, this property is unused in the 6.X 

Desired behavior

Should remove this invalid property also.

Mention any other details that might be useful (optional)

If yes, I think I can help make a PR to angular/devkit repo.