Added feature checking tests

Tests/test_features.py

@@ -0,0 +1,21 @@
+from helper import unittest, PillowTestCase
+
+from PIL import features
+
+
+class TestFeatures(PillowTestCase):
+
+    def test_check_features(self):
+        for feature in features.modules:
+            self.assertTrue(features.check_module(feature) in [True, False, None])
+        for feature in features.codecs:
+            self.assertTrue(features.check_codec(feature) in [True, False])
+
+    def test_supported_features(self):
+        self.assertTrue(type(features.get_supported_modules()) is list)
+        self.assertTrue(type(features.get_supported_codecs()) is list)
+
+if __name__ == '__main__':
+    unittest.main()
+
+# End of file