feat(production backend dockerfile) & enhanced(backend deps) & fix(userInfo bugs)

* Dropped the use of Pandas & updated loading scripts accordingly
* Separated python requirements files
* Updated Dockerfile to be able to also build a production ready image (without dev dependencies)
* Backend images size cut in more than half 🎉
* Updated a bit the documentation related to Docker
* CI now depends on clear image tags
* Fixed the serializers of User and enhanced frontend of userinfo
* Fixed wrong compose in frontend

Fixes #108 #109 #104
Linked to #66 for new prod dockerfile
9 jobs for master in 3 minutes and 14 seconds (queued for 2 seconds)
Status Job ID Name Coverage
  Check
passed #505265
docker
check_back

00:00:17

passed #505266
docker
check_front

00:00:49

 
  Test
passed #505267
docker
test_back

00:00:50

94.0%
passed #505268
docker
test_frontend

00:00:16

 
  Lint
passed #505270
docker
eslint

00:00:21

passed #505269
docker
flake8

00:00:13

 
  Svg Gen Docu
passed #505271
docker
generate_UML_svg

00:00:13

 
  Documentation
passed #505272
docker
pages

00:00:12

 
  Deploy
passed pages:deploy

00:00:00