Bump karma-coverage-istanbul-reporter from 2.0.5 to 2.0.6

Bumps [karma-coverage-istanbul-reporter](https://github.com/mattlewis92/karma-coverage-istanbul-reporter) from 2.0.5 to 2.0.6.
- [Release notes](https://github.com/mattlewis92/karma-coverage-istanbul-reporter/releases)
- [Changelog](https://github.com/mattlewis92/karma-coverage-istanbul-reporter/blob/master/CHANGELOG.md)
- [Commits](https://github.com/mattlewis92/karma-coverage-istanbul-reporter/compare/v2.0.5...v2.0.6)
Signed-off-by: dependabot-preview[bot] <support@dependabot.com>