fix test: "Yes" is the first level, thus the event level

Author: hfrick

tests/testthat/test_boost_tree_xgboost.R

@@ -210,7 +210,7 @@ test_that('submodel prediction', {
 
   mp_res <- multi_predict(class_fit, new_data = wa_churn[1:4, vars], trees = 5, type = "prob")
   mp_res <- do.call("rbind", mp_res$.pred)
-  expect_equal(mp_res[[".pred_No"]], pred_class)
+  expect_equal(mp_res[[".pred_Yes"]], pred_class)
 
   expect_error(
     multi_predict(class_fit, newdata = wa_churn[1:4, vars], trees = 5, type = "prob"),