Why org.testng becomes Unresolvable reference in kotlin tests?

kotlin: 1.1.4-2

These kotlin tests were ok in kotlin plugin 1.1.3-2, but when upgraded to 1.1.4, tests compile error with “org.testng” red.

I got the same problem with latest version, 1.2.10, any solutions here?

In case someone need it, the test case should reside in /src/test/kotlin/, then the testng will be recognized correctly.