* Added a user page to show user information
* Updated backend to handle the new data
* Added backend test related to this
* User can now be anonymous
* NB: only users with level == authenticated user can be anonymous on the site
* Backend serializers updated to return the pseudonyme of the user
* Added a boolean field form element

Fixes #64 #65

Other fixes:

* Added basic test for userData
* Fixed bug in ReadOnly permission
* Fixed typos/bugs in new CrudActions
* Enhance fields declaration in abstract serializers
* Changed jsx linting rules
* Moved generic editors files
* Updated network errors handling