GitLab

* Cleaned all init files
* Infer the serializer from the model instead of having it in the models
* Updated the doc accordingly
* Fixed typos

Fixes #93
Fixes #85

* Added new BaseModel /serializer/viewsets
* Change names of abstract models/serializers/viewsets
* Folder structure changed in tha backend
* Added some backend test
* Corrected bug related to moderation on non versionned modeles
* Corrected bug related to no post permissions
* Updated doc accordingly

Fixes #91

Repo structure complete redesign
Fixes #38