Bump numpy from 1.18.2 to 1.18.3

Bumps [numpy](https://github.com/numpy/numpy) from 1.18.2 to 1.18.3.
- [Release notes](https://github.com/numpy/numpy/releases)
- [Changelog](https://github.com/numpy/numpy/blob/master/doc/HOWTO_RELEASE.rst.txt)
- [Commits](numpy/numpy@v1.18.2...v1.18.3)

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

requirements.txt

@@ -1,5 +1,5 @@
 pymatgen==2020.4.2
 pandas==1.0.3
 tensorflow==2.1.0
-numpy==1.18.2
+numpy==1.18.3
 monty==3.0.2