Iris test now fixed at 1 thread to try to increase stability

Author: TomFinley

test/Microsoft.ML.Tests/ScenariosWithDirectInstantiation/IrisPlantClassificationTests.cs

@@ -70,7 +70,7 @@ public void TrainAndPredictIrisModelUsingDirectInstantiationTest()
                 trans = NormalizeTransform.CreateMinMaxNormalizer(env, trans, "Features");
 
                 // Train
-                var trainer = new SdcaMultiClassTrainer(env, new SdcaMultiClassTrainer.Arguments());
+                var trainer = new SdcaMultiClassTrainer(env, new SdcaMultiClassTrainer.Arguments() { NumThreads = 1 } );
 
                 // Explicity adding CacheDataView since caching is not working though trainer has 'Caching' On/Auto
                 var cached = new CacheDataView(env, trans, prefetch: null);