fix missing role info when creating user

[thomasDOTwtf]

adding a default user role to newly created objects.
This is an alternate approach to issue #11

[TimoStahl]

We had the same issues, this change fixed it

[thomasDOTwtf]

@LizardM4 might you be able to review and merge?

[5p4k]

@thomasDOTwtf sure!

@BlueTeck It seems sensible that a new user assumes the app user role by default, but I think we should use the Role::APP_USER constant from Kanboard/Core/Security/Role rather than hardcoding the value.

[TimoStahl]

In my private fork, I've changed the constructor instead and didn't pass an default role.

https://github.com/trajche/SamlAuth/blob/master/User/SamlUserProvider.php#L39

public function __construct($username, $email, $name, $role = '')