Bump coveralls from 3.0.3 to 3.0.6 in /js

Bumps [coveralls](https://github.com/nickmerwin/node-coveralls) from 3.0.3 to 3.0.6.
- [Release notes](https://github.com/nickmerwin/node-coveralls/releases)
- [Commits](https://github.com/nickmerwin/node-coveralls/commits

)

Signed-off-by: dependabot-preview[bot] <support@dependabot.com>