OpenML uses an API key to authenticate a user. The API repository also needs an API key in order to run tests against the OpenML server. The API key used for the tests are linked to a special test user. Since API keys are private, we have to use private environment variables for travis-ci. The API key is stored in an environment variable OPENMLAPIKEY in travis-ci. To encrypt an API key for use on travis-ci use the following command to create a private string to put into the .travis.yml file

travis encrypt OPENMLAPIKEY=secretvalue --add