Normalizer bug - KeyError: '\\u'

[GokulNC]

After the PR #200 was merged, I face the following error:

>>> from hazm import Normalizer
>>> h=Normalizer()
>>> h.normalize("hi")
Traceback (most recent call last):
  File "/usr/lib/python3.8/sre_parse.py", line 1039, in parse_template
    this = chr(ESCAPES[this][1])
KeyError: '\\u'

During handling of the above exception, another exception occurred:

Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
  File "/home/ubuntu/.local/lib/python3.8/site-packages/hazm/Normalizer.py", line 75, in normalize
    text = self.character_refinement(text)
  File "/home/ubuntu/.local/lib/python3.8/site-packages/hazm/Normalizer.py", line 106, in character_refinement
    text = pattern.sub(repl, text)
  File "/usr/lib/python3.8/re.py", line 327, in _subx
    template = _compile_repl(template, pattern)
  File "/usr/lib/python3.8/re.py", line 318, in _compile_repl
    return sre_parse.parse_template(repl, pattern)
  File "/usr/lib/python3.8/sre_parse.py", line 1042, in parse_template
    raise s.error('bad escape %s' % this, len(this))
re.error: bad escape \u at position 0

FYI, I am on the latest commit and python 3.7

---

To fix the error, I am currently using the version before the PR was merged:

pip uninstall hazm && pip install git+git://github.com/sobhe/hazm.git@0d196cf31ac162414b70cfd254f7efe9704b238b

[ghost]

This problem is not there anymore.