royalty fee manager tests

[VictorONN]

Hello, tests for #36

3 tests appear to fail. The first two am the most odd since my approach is similar to the references :

1. test_upgrade_with_class_hash_zero() fails even though the implementation is similar https://github.com/OpenZeppelin/cairo-contracts/blob/8372bc9ef2b4306cf02a60421e5d6843ebcd0c64/src/tests/upgrades/test_upgradeable.cairo#L35

2. test_upgrade_event_when_successful() also fails despite following similar implementation https://github.com/OpenZeppelin/cairo-contracts/blob/8372bc9ef2b4306cf02a60421e5d6843ebcd0c64/src/tests/upgrades/test_upgradeable.cairo#L43

3. And test_calculate_royalty_fee_and_get_recipient_success() fails with
   Failure data:
   Got an exception while executing a hint:
   Class hash 0x049b61ff596ba762ad66791c8204943217e5f1b94a28b34ce4ca2f9ad4ff2b6c is already declared

[Realkayzee]

I will rectify this and make a new PR

[Realkayzee]

@VictorONN I already worked on it and added it to my PR