public async Task <IHttpActionResult> RemoveAMembre(int groupID, int ownerID, int userID)
        {
            var group = await db.Groups.FirstOrDefaultAsync(g => g.GroupID == groupID);

            if (group == null)
            {
                return(NotFound());
            }

            var user = await db.Users.FirstOrDefaultAsync(u => u.UserID == userID);

            if (user == null)
            {
                return(NotFound());
            }

            var owner = await db.Users.FirstOrDefaultAsync(u => u.UserID == ownerID);

            if (owner == null)
            {
                return(NotFound());
            }

            await db.RemoveAUser(groupID, ownerID, userID);

            return(Ok());
        }