I had inadvertently committed two files with Windows style 'CRLF'
(``\r\n``) line endings. This commit changes 
``docutils/test/conftest.py`` and ``.gitattributes`` to use Unix
style 'LF' (``\n``) endings.

We additionally specify that Unix style line endings are only
enforced in the ``docutils`` directory, as there are around 20 files
in the sandbox that use Windows style line endings, and I don't want
to change these at the moment.

git-svn-id: https://svn.code.sf.net/p/docutils/code/trunk@9334 929543f6-e4f2-0310-98a6-ba3bd3dd1d04

* Mark images, videos, and binary document formats (ODT, PDF) as binary
  files. 
* Mark all text files as using Unix-style (LF) line endings.
* Use built-in ``git diff`` headers for specific languages.
* Specify files that are not ASCII or UTF-8, and the encoding that such files
  should be viewed in.

Reference: https://git-scm.com/docs/gitattributes

git-svn-id: https://svn.code.sf.net/p/docutils/code/trunk@9333 929543f6-e4f2-0310-98a6-ba3bd3dd1d04

git-svn-id: https://svn.code.sf.net/p/docutils/code/trunk@9332 929543f6-e4f2-0310-98a6-ba3bd3dd1d04