Migrate to travis-ci.com

[lrozenblyum]

(NOTE: the migration for existing projects hosted in travis-ci.org to com is not supported yet)

https://blog.travis-ci.com/2018-05-02-open-source-projects-on-travis-ci-com-with-github-apps?utm_source=email&utm_campaign=2may_release

To test

• Push - build
• Pull request - build
• SonarCloud integration!
• Build badge must be updated
• Build history - extract to a separate ticket: Travis history migration #286

[lrozenblyum]

The following repositories cannot be migrated to travis-ci.com at this time because they are currently active on our legacy platform travis-ci.org. This feature will be available shortly. Please read our docs on open source migration to learn more.

https://travis-ci.com/account/repositories

[lrozenblyum]

It's mandatory to be executed till 31 Jan 2019, or we'll lose part of GitHub <-> Travis integration