client.truncate test timed out on Mac Travis

https://travis-ci.org/DynamoRIO/dynamorio/jobs/309810811

32/51 Test #117: code_api|client.truncate .....................***Failed  Required regular expression not found.Regex=[^thank you for testing the client interface
Hello, world!
$
] 90.16 sec
thank you for testing the client interface

If this happens again on just this test we can increase its timeout. It's not clear why this one would be so slow: single-instr-bbs, but it's just the hello,world app, right?