[Test] Added edit distance test that includes deletion.

Author: exterkamp

tests/test_edit_distance.py

@@ -4,6 +4,7 @@
 class TestEditDistance(unittest.TestCase):
 
     def test_edit_distance(self):
-
         self.assertEqual(['Substitute h', 'Insert l', 'Substitute l'], calculate_edit_distance('hello','teio'))
-
+    
+    def test_deletion_required(self):
+        self.assertEqual(['Delete o', 'Delete n', 'Delete e', 'Delete  '], calculate_edit_distance('two','one two'))