autodoc tries to import classes as modules

[amueller]

From sphinx-doc/sphinx#3768 as I suspect it might be a numpydoc issue after all.

After updating sphinx and numpydoc, I get

WARNING: /home/andy/checkout/scikit-learn/doc/modules/generated/sklearn.preprocessing.RobustScaler.rst:92: (WARNING/2) autodoc: failed to import method 'RobustScaler.__init__' from module 'sklearn.preprocessing.data.RobustScaler'; the following exception was raised:
Traceback (most recent call last):
  File "/home/andy/anaconda3/lib/python3.5/site-packages/sphinx/ext/autodoc.py", line 658, in import_object
    __import__(self.modname)
ImportError: No module named 'sklearn.preprocessing.data.RobustScaler'; 'sklearn.preprocessing.data' is not a package

for every class in the package.

It looks like the modname is wrong as it is the class and not the module. I'm not sure what should be imported at this point, though. The class? Importing a method doesn't seem to make a lot of sense...

Repo to reproduce:
https://github.com/amueller/sphinx-debug

WARNING: /home/andy/checkout/sphinx-debug/doc/modules/generated/blablub.BaseEstimator.rst:28: (WARNING/2) autodoc: failed to import method 'BaseEstimator.__init__' from module 'blablub.BaseEstimator'; the following exception was raised:
Traceback (most recent call last):
  File "/home/andy/checkout/sphinx/sphinx/ext/autodoc.py", line 657, in import_object
    __import__(self.modname)

[amueller]

Fixed in master, possibly via #93, thanks @jschueller for the pointer.