[skeleton] Have setuptools install data files
Just add `include_package_data=True` as recommended by
`setuptools documentation`_ as this appears to be the simplest way to handle
this.
Related to #13001466.
.. _`setuptools documentation`: \
http://setuptools.readthedocs.io/en/latest/setuptools.html#including-data-files
addressbook
basket
blog
book
calendar
comment
company
email
file
folder
i18ncontent
keyword
link
mailinglist
person
tag
timeseries
vcsfile