fixed jsbeautifier version for now

[kzidane]

Apparently the latest version of jsbeautifier is buggy, breaking installation of style50. Specified fixed version for now:

$ pip install jsbeautifier
Collecting jsbeautifier
  Downloading jsbeautifier-1.7.0.tar.gz
    Complete output from command python setup.py egg_info:
    Traceback (most recent call last):
      File "<string>", line 1, in <module>
      File "/tmp/pip-build-xiod3y70/jsbeautifier/setup.py", line 6, in <module>
        from jsbeautifier.__version__ import __version__
      File "/tmp/pip-build-xiod3y70/jsbeautifier/jsbeautifier/__init__.py", line 11, in <module>
        from jsbeautifier.javascript.options import BeautifierOptions
    ImportError: No module named 'jsbeautifier.javascript'
    
    ----------------------------------------
Command "python setup.py egg_info" failed with error code 1 in /tmp/pip-build-xiod3y70/jsbeautifier/

[kzidane]

beautifier/js-beautify#1250