Bump numpy from 1.15.4 to 1.22.0

Bumps [numpy](https://github.com/numpy/numpy) from 1.15.4 to 1.22.0.
- [Release notes](https://github.com/numpy/numpy/releases)
- [Changelog](https://github.com/numpy/numpy/blob/main/doc/HOWTO_RELEASE.rst)
- [Commits](numpy/numpy@v1.15.4...v1.22.0)

---
updated-dependencies:
- dependency-name: numpy
  dependency-type: direct:production
...

Signed-off-by: dependabot[bot] <support@github.com>

requirements.txt

@@ -8,7 +8,7 @@ mako
 matplotlib >= 2.2.2
 mkdocs-material >= 5.1.7
 mkdocs-material-extensions
-numpy == 1.15.4
+numpy == 1.22.0
 paramiko == 2.6.0
 pandas
 py3Dmol == 0.8.0