Update test_learning.py (aimacode#483)

Author: antmarakis

tests/test_learning.py

@@ -55,13 +55,17 @@ def test_k_nearest_neighbors():
 
     kNN = NearestNeighborLearner(iris,k=3)
     assert kNN([5,3,1,0.1]) == "setosa"
+    assert kNN([6,5,3,1.5]) == "versicolor"
+    assert kNN([7.5,4,6,2]) == "virginica"
 
 
 def test_decision_tree_learner():
     iris = DataSet(name="iris")
 
     dTL = DecisionTreeLearner(iris)
     assert dTL([5,3,1,0.1]) == "setosa"
+    assert dTL([6,5,3,1.5]) == "versicolor"
+    assert dTL([7.5,4,6,2]) == "virginica"
 
 
 def test_neural_network_learner():