Update Rinkeby token list

[nlordell]

Currently, our default token list has just three tokens:

$ curl https://raw.githubusercontent.com/Uniswap/token-lists/master/test/schema/bigexample.tokenlist.json  | jq '.tokens[] | select(.chainId == 4)'
{
  "address": "0xc778417E063141139Fce010982780140Aa0cD5Ab",
  "chainId": 4,
  "name": "Wrapped Ether",
  "symbol": "WETH",
  "decimals": 18
}
{
  "address": "0xc7AD46e0b8a400Bb3C915120d284AafbA8fc4735",
  "chainId": 4,
  "name": "Dai Stablecoin",
  "symbol": "DAI",
  "decimals": 18
}
{
  "address": "0xF9bA5210F91D0474bd1e1DcDAeC4C58E359AaD85",
  "chainId": 4,
  "name": "Maker",
  "symbol": "MKR",
  "decimals": 18
}

After fixing #23, we could use a larger list, for example here are the lists used by the frontend.

Original issue gnosis/gp-v2-trading-bot#24 by @fedgiac