Update pip and pip-tools version to fix make upgrades

[edx-requirements-bot]

Additional information from script execution

Python code cleanup by the cleanup-python-code Jenkins job.

This pull request was generated by the cleanup-python-code Jenkins job, which ran

``` pip install --upgrade pip;pip install --upgrade pip-tools;pip-compile -v --allow-unsafe --rebuild -o requirements/pip.txt requirements/pip.in;pip-compile --upgrade -o requirements/pip-tools.txt requirements/pip-tools.in;make upgrade ```

The following packages were installed: ``