Added CreditNote Pdf and Payment methods

[paulosouza-stark]

Credit Note

GET Pdf

Request

import java.io.File;
import java.io.InputStream;
import java.nio.file.StandardCopyOption;
import com.starkbank.*;

InputStream pdf = CreditNote.pdf("5646210941583360");

java.nio.file.Files.copy(
    pdf,
    new File("credit-note.pdf").toPath(),
    StandardCopyOption.REPLACE_EXISTING
);

GET Payment

Request

import java.io.File;
import java.io.InputStream;
import java.nio.file.StandardCopyOption;
import com.starkbank.*;

InputStream pdf = CreditNote.payment("5950134772826112");

java.nio.file.Files.copy(
    pdf,
    new File("credit-note-payment.pdf").toPath(),
    StandardCopyOption.REPLACE_EXISTING
);