tests: fix isort compatibility
# under the terms of the MIT License; see LICENSE file for more details.
pydocstyle invenio && \
-isort -rc -c -df **/*.py && \
+isort invenio tests --check-only --diff && \
check-manifest --ignore ".travis-*" && \
sphinx-build -qnNW docs docs/_build/html && \
python setup.py test && \
