The Travis-CI no longer build this project.
It says
Since June 15th, 2021, the building on travis-ci.org is ceased. Please use travis-ci.com from now on.
Travis CI - Test and Deploy Your Code with Confidence is in read-only mode. The historical data can be downloaded to external file storage.
They still offer a "free" plan with the following description:
However, the project will no longer be able to build after we run out of 10000 credits.
Although they say they may be able to give more credits for open source projects upon requests,
Free for open source. We love the Open Source Community, and to show how much we love it, upon validated request placed with our Support Team you may receive free OSS credits for your public builds.
The Travis-CI no longer build this project. It says
They still offer a "free" plan with the following description:
However, the project will no longer be able to build after we run out of 10000 credits.
Although they say they may be able to give more credits for open source projects upon requests,
It's questionable and cumbersome anyways.
Therefore, sadly, we decided to get rid of Travis-CI. Fortunately, we can use CircleCI :)