Test word lists with Unicode

For testing issue 19. Right now these tests fail on Windows with Python 2.7:
```
E.E...
======================================================================
ERROR: testAddUnicodeWordsToWordList (__main__.WordListApiTest)
----------------------------------------------------------------------
Traceback (most recent call last):
  File "tests\WordListApiTest.py", line 117, in testAddUnicodeWordsToWordLi
    self.authToken, body=wordsToAdd)
  File "./wordnik\WordListApi.py", line 191, in addWordsToWordList
    postData, headerParams)
  File "./wordnik\swagger.py", line 61, in callAPI
    data = self.sanitizeForSerialization(postData)
  File "./wordnik\swagger.py", line 103, in sanitizeForSerialization
    return [self.sanitizeForSerialization(subObj) for subObj in obj]
  File "./wordnik\swagger.py", line 112, in sanitizeForSerialization
    for (key, val) in objDict.iteritems()
  File "./wordnik\swagger.py", line 113, in <dictcomp>
    if key != 'swaggerTypes'}
  File "./wordnik\swagger.py", line 110, in sanitizeForSerialization
    objDict = obj.__dict__
AttributeError: 'unicode' object has no attribute '__dict__'

======================================================================
ERROR: testDeleteUnicodeWordsFromList (__main__.WordListApiTest)
----------------------------------------------------------------------
Traceback (most recent call last):
  File "tests\WordListApiTest.py", line 139, in testDeleteUnicodeWordsFromL
    body=wordsToRemove)
  File "./wordnik\WordListApi.py", line 287, in deleteWordsFromWordList
    postData, headerParams)
  File "./wordnik\swagger.py", line 61, in callAPI
    data = self.sanitizeForSerialization(postData)
  File "./wordnik\swagger.py", line 103, in sanitizeForSerialization
    return [self.sanitizeForSerialization(subObj) for subObj in obj]
  File "./wordnik\swagger.py", line 112, in sanitizeForSerialization
    for (key, val) in objDict.iteritems()
  File "./wordnik\swagger.py", line 113, in <dictcomp>
    if key != 'swaggerTypes'}
  File "./wordnik\swagger.py", line 110, in sanitizeForSerialization
    objDict = obj.__dict__
AttributeError: 'unicode' object has no attribute '__dict__'

----------------------------------------------------------------------
Ran 6 tests in 7.516s

FAILED (errors=2)
```
Merge pull request #20 from hugovk/patch-1

Test word lists with Unicode