missing files for testing

[gititGoro]

Hi there,
When I tried to run the tests, I noticed a great deal of implied dependencies but no package.json.
I also came across lines like this:

import {getTruffleContractInstance} from '../../utils/truffle/truffle-core-utils';

but none of truffle's libraries in any of their repos have this exported function (as far as I can tell).

This line

import {NIL_ADDRESS, ETHEREUM_ADDRESS} from '../../utils/constants';

looks very Aave specific since the source code contains that dummy ethereum address.

I think there's a toplevel utils folder that hasn't been committed.

[katalonne]

@The-3D @ernesto-usal ???