message: Migrate org.mockito.Matchers#{isA, same, isNull, notNull} to org.mockito.ArgumentMatchers
  The former are deprecated and replaced by the latter in Mockito 2.
diff: @@ -18,7 +18,7 @@ package com.google.crypto.tink.integration.awskms;
  import static org.junit.Assert.assertArrayEquals;
  import static org.junit.Assert.fail;
  -import static org.mockito.Matchers.isA;
  +import static org.mockito.ArgumentMatchers.isA;
  import static org.mockito.Mockito.mock;
  import static org.mockito.Mockito.when;
  