`VaultManager`

[shine2lay]

This is just to formalize our discussion we had on the call regarding vaultList,

If we look at the maker dao system, they use a cdpManager , https://github.com/makerdao/dss-cdp-manager/blob/master/src/DssCdpManager.sol . This is where the cdp ID comes from, I am not sure but i think this mean that there can also be vault where it is not listed if user use the vat directly in maker dao

[mrosendin]

VaultManager should remove the extra steps of:

• (1) needing to deposit collateral before staking/borrowing
• (2) needing to withdraw and deposit ERC20 tokens from/into the vault when borrowing/repaying
• (3) needing to collect interest and withdraw ERC20 tokens from vault to receive profits

[mrosendin]

@shine2lay I created VaultManager in f7d822e but quickly realized that you can't pass msg.sender to the target contract.

I started looking into how Maker does this, and it looks like they give the VaultManager contract the permission to manage the vault for them (or something like that)

[shine2lay]

Vault manager is probably gonna be a library which user can use with their wallet contract, that way vault manager is not the caller but the wallet contract.

[mrosendin]

Related: #279