Bump numpy from 1.18.5 to 1.21.0 in /ChurnModel

Bumps [numpy](https://github.com/numpy/numpy) from 1.18.5 to 1.21.0.
- [Release notes](https://github.com/numpy/numpy/releases)
- [Changelog](https://github.com/numpy/numpy/blob/main/doc/HOWTO_RELEASE.rst.txt)
- [Commits](numpy/numpy@v1.18.5...v1.21.0)

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

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Author: dependabot[bot]

ChurnModel/training_pipeline_requirements.txt

@@ -2,7 +2,7 @@
 # Then see installed versions
 # pip freeze|grep joblib
 # > joblib==0.14.1
-numpy==1.18.5
+numpy==1.21.0
 pandas==0.25.3
 sklearn-pandas==1.7.0
 lightgbm==2.3.0