Enable TravisCI on kubernetes-sigs/aws-encryption-provider

[micahhausler]

Organization or repository

https://github.com/kubernetes-sigs/aws-encryption-provider

Name of integration

TravisCI

Link to integration website

https://travis-ci.org/

Describe what is attempting to be accomplished

I'd like TravisCI integration added to the repository.

Additional context for request

I do not want merges to be blocked by failing tests

[cblecker]

@micahhausler Is there a reason you need travis as opposed to a prow job? We don't explicitly disallow travis, but we prefer prow where possible.

[micahhausler]

I'm not opposed to prow, is there a getting-started guide?

[cblecker]

https://git.k8s.io/test-infra/prow/jobs.md