Bump travis from 1.8.10 to 1.8.11
Bump travis from 1.8.10 to 1.8.11

Bumps [travis](https://github.com/travis-ci/travis.rb) from 1.8.10 to 1.8.11.
- [Release notes](https://github.com/travis-ci/travis.rb/releases)
- [Commits](https://github.com/travis-ci/travis.rb/commits)

Signed-off-by: dependabot-preview[bot] <5bdcd3c0d4d24ae3e71b3b452a024c6324c7e4bb@dependabot.com>
coderdojo-japan/coderdojo.jp,yasslab/coderdojo.jp,coderdojo-japan/coderdojo.jp,coderdojo-japan/coderdojo.jp,yasslab/coderdojo.jp,yasslab/coderdojo.jp,coderdojo-japan/coderdojo.jp