The test is vary flaky on Travis.
Seems that since (https://github.com/etcd-io/etcd/issues/7724) the
client is expected to simply ignore whether server is in AuthDisabled
mode even if the user supplies credentials.
The tests used to:
* use very large cluster (10 nodes)
* set very low timeout (1 sec)
Such setup led to frequent deadlineExceed errors or following failures:
=== RUN TestGetTokenWithoutAuth
{"level":"warn","ts":"2020-08-04T16:50:48.686+0200","caller":"clientv3/retry_interceptor.go:62","msg":"retrying of unary invoker failed","target":"endpoint://client-35573307-1ee5-441b-acc7-d073f0bd7de5/localhost:69820396562031027440","attempt":0,"error":"rpc error: code = Unavailable desc = etcdserver: leader changed"}
user_test.go:151: other errors:etcdserver: leader changed
--- FAIL: TestGetTokenWithoutAuth (10.91s)