Allow build on SLE-15

OBS-URL: https://build.opensuse.org/package/show/devel:languages:python/python-docutils?expand=0&rev=76

python-docutils.spec

@@ -68,6 +68,9 @@ for i in tools/rst*; do mv "$i" "${i/.py}"; done
 sed -i "s|'tools/\(rst.*\)\.py'|'tools/\1'|" setup.py
 find . -name \*.mp4 -print -exec chmod -x '{}' \;
 
+# Actually seems to work with Python 3.6
+sed -i -e '/python_requires/s/7/6/' setup.py
+
 %build
 %pyproject_wheel