Refactored Tree.pm . Deleting global variable tree and change by self.

Signed-off-by: Victor Cotrim <cotrim149@gmail.com>
Signed-off-by: Macartur de Sousa <macartur.sc@gmail.com>
Adding method test, used variables name test and local variable name test in Tree.t

Signed-off-by: Victor Cotrim <cotrim149@gmail.com>
Signed-off-by: Macartur de Sousa <macartur.sc@gmail.com>