Cleanup.

.gitignore

@@ -1,2 +1,3 @@
 os/code/target/*
-database/code/__pycache__/
+database/code/__pycache__
+*.class

oop/code/OopBankAccount.java

@@ -1,23 +0,0 @@
-public class OopBankAccount {
-    private Integer number;
-    private Integer balance;
-
-    public OopBankAccount(Integer number, Integer balance) {
-        this.number = number;
-        this.balance = balance;
-    }
-
-    void deposit(Integer amount) {
-        this.balance  += amount;
-    }
-
-    void withdraw(Integer amount) {
-        this.balance  += amount;
-    }
-
-    void transfer(OopBankAccount destination, Integer amount) {
-        this.withdraw(amount);
-        destination.deposit(amount);
-    }
-
-}