Refactor: Refactored IdentificadorDeToken to use hashmap instead of if/else statements (Julio/Lucas)
Refactor: Fixed ValidadorDeAtribuicao identation (Julio/Lucas)
Refactor: Changed attributes visibility (Julio)
Refactor: refactored method validaVariavel. Not a big deal (Julio)
Refactor: added method to get the map of tokens
Refactor: Changed attributes visibility to private