Bump numpy from 1.19.3 to 1.19.4

Bumps [numpy](https://github.com/numpy/numpy) from 1.19.3 to 1.19.4.
- [Release notes](https://github.com/numpy/numpy/releases)
- [Changelog](https://github.com/numpy/numpy/blob/master/doc/HOWTO_RELEASE.rst.txt)
- [Commits](numpy/numpy@v1.19.3...v1.19.4)

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

requirements.txt

@@ -6,7 +6,7 @@ docker>=4.2.0
 domdf-python-tools>=1.7.0
 jinja2>=2.10.1
 numpy>=1.19.1; platform_system != "Windows"
-numpy==1.19.3; platform_system == "Windows"
+numpy==1.19.4; platform_system == "Windows"
 pymassspec>=2.2.20
 requests>=2.22.0
 sdjson>=0.2.6