Added tests for information_content (aimacode#753)

* Added tests for information_content

Added some tests for information_content function from learning.py

* Added test for information_content

Author: ayushjain19

tests/test_learning.py

@@ -165,6 +165,15 @@ def test_decision_tree_learner():
     assert dTL([7.5, 4, 6, 2]) == "virginica"
 
 
+def test_information_content():
+    assert information_content([]) == 0
+    assert information_content([4]) == 0
+    assert information_content([5, 4, 0, 2, 5, 0]) > 1.9
+    assert information_content([5, 4, 0, 2, 5, 0]) < 2
+    assert information_content([1.5, 2.5]) > 0.9
+    assert information_content([1.5, 2.5]) < 1.0
+
+
 def test_random_forest():
     iris = DataSet(name="iris")
     rF = RandomForest(iris)