Bump requests from 2.24.0 to 2.25.0

Bumps [requests](https://github.com/psf/requests) from 2.24.0 to 2.25.0.
- [Release notes](https://github.com/psf/requests/releases)
- [Changelog](https://github.com/psf/requests/blob/master/HISTORY.md)
- [Commits](https://github.com/psf/requests/compare/v2.24.0...v2.25.0)

sphinx-doc/requirements_sphinx.txt

@@ -44,8 +44,8 @@ python-intervals==1.10.0
 pytz==2020.4
 PyWavelets==1.1.1
 recommonmark==0.6.0
+requests==2.25.0
 regex==2020.11.13
-requests==2.24.0
 scikit-learn==0.22.1
 scipy==1.5.4
 six==1.14.0