Add flower as a dev dependency

[samdoran]

Description

Add flower as a dev dependency to provide bette visibly into celery tasks during development.

Testing

1. Checkout Branch
2. Run pipenv install --dev
3. Run celery -A koku flower
4. Open http://localhost:5555

Release Notes

• proposed release note

* Add [flower](https://flower.readthedocs.io/en/latest/index.html) as a development dependency

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 94.2%. Comparing base (c7eb09d) to head (1da3029).
Report is 1 commits behind head on main.

Additional details and impacted files

@@          Coverage Diff          @@
##            main   #5189   +/-   ##
=====================================
  Coverage   94.2%   94.2%           
=====================================
  Files        376     376           
  Lines      31230   31230           
  Branches    3725    3725           
=====================================
+ Hits       29411   29413    +2     
+ Misses      1160    1157    -3     
- Partials     659     660    +1     

[bacciotti]

side note: it should be run inside koku/koku (or wherever the celery.py file is).

[bacciotti]

lgtm, worked.