error in pypi package: AttributeError: type object 'ClassHolder' has no attribute 'start'

After grabbing codetalker from github and css from pypi:

> Python 2.7 (r27:82500, Sep 29 2010, 23:01:31)
> [GCC 4.5.1 20100924 (Red Hat 4.5.1-4)] on linux2
> Type "help", "copyright", "credits" or "license" for more information.
>
> # from css import css
>
> Traceback (most recent call last):
> File "", line 1, in
> File "/home/sirpengi/virtualenv/zanderloo/lib/python2.7/site-packages/css/**init**.py", line 2, in
> from grammar import grammar, t as css
> File "/home/sirpengi/virtualenv/zanderloo/lib/python2.7/site-packages/css/grammar.py", line 64, in
> @t.translates(ast.start)
> AttributeError: type object 'ClassHolder' has no attribute 'start'

Start by reproducing the Python 2.7 import using the css package from PyPI and the codetalker version from GitHub. Inspect css/__init__.py and css/grammar.py, especially the ast.start reference at grammar.py line 64; done means importing css no longer raises this AttributeError.

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