Bump numpy from 1.18.4 to 1.19.2

Bumps [numpy](https://github.com/numpy/numpy) from 1.18.4 to 1.19.2.
- [Release notes](https://github.com/numpy/numpy/releases)
- [Changelog](https://github.com/numpy/numpy/blob/master/doc/HOWTO_RELEASE.rst.txt)
- [Commits](numpy/numpy@v1.18.4...v1.19.2)

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

requirements.txt

@@ -14,4 +14,4 @@ icalendar==4.0.7
 sqlalchemy==1.3.19
 filelock==3.0.12
 alembic==1.4.3
-numpy==1.18.4
+numpy==1.19.2