remove trailing spaces

fixing get_roles unit test

list of roles and not a uniq role for get_groups

fix unit tests + add graph method ...

* fix unit tests on roles (adding mandatory description)
* adding a method to get roles graph in json

implementing a method to get groups to remove ...

* implement a way to remove roles from a user
  without removing groups of roles the user keeps

adding unit tests

simplify roles configuration (backend groups)

add methods for class Roles + unit tests ...

* adding get_allroles (list all available roles)
* adding get_display_name (get display name of a role)
* add various unit tests

unit test + admin roles fix ...

* adding various unit tests
* now admin roles are inherited (ex admin-lv2 is admin -> admin-lv3 is admin
* adding an exception when requesting groups for none existant role

more complex unit test for get_roles

adding a test for get_roles

implementing nesting roles

adding an exception for failures to open role file

fix on unit tests for roles

adding test cases and reworking test env