Security review of 3rd party services

We are doing our annual security review of 3rd party services. The goal is to remove permissions of services that are no longer used in this repository's CI workflow.

Services that need to be reviewed:

- [ ] Travis CI for Open Source
- [ ] Coveralls
- [ ] StyleCI
- [ ] Travis CI
- [ ] AppVeyor
- [ ] AppVeyor CI
- [ ] CircleCI
- [ ] Code Climate
- [ ] Packagist