word-count: Remove unicode test case

As discussed in exercism/problem-specifications#441

Fixes exercism#416

exercises/word-count/example.py

@@ -1,16 +1,8 @@
 from collections import Counter
 
 
-# to be backwards compatible with the old Python 2.X
-def decode_if_needed(string):
-    try:
-        return string.decode('utf-8')
-    except AttributeError:
-        return string
-
-
 def word_count(text):
     def replace_nonalpha(char):
         return char.lower() if char.isalnum() else ' '
-    text = ''.join(replace_nonalpha(c) for c in decode_if_needed(text))
+    text = ''.join(replace_nonalpha(c) for c in text)
     return Counter(text.split())

exercises/word-count/word_count_test.py

@@ -1,17 +1,8 @@
-# -*- coding: utf-8 -*-
 import unittest
 
 from word_count import word_count
 
 
-# to be backwards compatible with the old Python 2.X
-def decode_if_needed(string):
-    try:
-        return string.decode('utf-8')
-    except AttributeError:
-        return string
-
-
 class WordCountTests(unittest.TestCase):
 
     def test_count_one_word(self):
@@ -78,12 +69,6 @@ def test_non_alphanumeric(self):
             word_count('hey,my_spacebar_is_broken.')
         )
 
-    def test_unicode(self):
-        self.assertEqual(
-            {decode_if_needed('до'): 1, decode_if_needed('свидания'): 1},
-            word_count('до🖖свидания!')
-        )
-
 
 if __name__ == '__main__':
     unittest.main()