Added users model for authentication with roles and user roles

private_gpt/users/api/v1/routers/roles.py

@@ -0,0 +1,18 @@
+from typing import Any, List
+
+from private_gpt.users import crud, schemas
+from private_gpt.users.api import deps
+from fastapi import APIRouter, Depends
+from sqlalchemy.orm import Session
+
+router = APIRouter(prefix='/roles', tags=['roles'])
+
+@router.get("/", response_model= List[schemas.Role])
+def get_roles(
+    db: Session = Depends(deps.get_db), skip: int = 0, limit: int = 100,
+) -> Any:
+    """
+    Retrieve all avaiable user roles.
+    """
+    roles = crud.roles_crud.get_multi(db, skip=skip, limit=limit)
+    return roles