Addresses in `relations.ts` should be case-insensitive

Spider currently expects addresses in `relations.ts` to be all lower case. We should make it case-insensitive.

e.g.
```
  '0xDbcd5BafBAA8c1B326f14EC0c8B125DB57A5cC4c': {
    artifact: 'contracts/ERC20.sol:ERC20',
  },
  ```
will not work right now