chore(deps): update prettier requirement from ~1.14.0 to ~1.15.2 (#1238)
chore(deps): update prettier requirement from ~1.14.0 to ~1.15.2 (#1238)

Updates the requirements on [prettier](https://github.com/prettier/prettier) to permit the latest version.
- [Release notes](https://github.com/prettier/prettier/releases)
- [Changelog](https://github.com/prettier/prettier/blob/master/CHANGELOG.md)
- [Commits](https://github.com/prettier/prettier/commits/1.15.2)

Signed-off-by: dependabot[bot] <5bdcd3c0d4d24ae3e71b3b452a024c6324c7e4bb@dependabot.com>
stryker-mutator/stryker,stryker-mutator/stryker,stryker-mutator/stryker