♻️ Use String Numbers for `assert` Statements

[sudo rm -rf --no-preserve-root /]

Fixes #14 (comment). Example:

assertEq(newContract, computedAddress, "100");
assertNotEq(newContract, zeroAddress, "200");
assertNotEq(newContract.code.length, 0, "300");
assertEq(newContract.balance, 0, "400");
assertEq(ERC20Mock(computedAddress).name(), arg1, "500");
assertEq(ERC20Mock(computedAddress).symbol(), arg2, "600");
assertEq(ERC20Mock(computedAddress).balanceOf(arg3), arg4, "700");