Setup correct filter to listen only on `ResolutionProposed` events

[potomak]

The topic is the hash of an event function signature.

Example

curl -X POST --data '{
  "jsonrpc": "2.0",
  "method": "eth_newFilter",
  "params": [
    {
      "topics": [
        "0x56b138798bd325f6cc79f626c4644aa2fd6703ecb0ab0fb168f883caed75bf32"
      ]
    }
  ],
  "id": 1
}' http://localhost:8545 | jq .

This filter will collect data about a specific event. To calculate the topic's hash run web3.sha3('TestEvent(string,uint256)') in a geth console. web3.sha3 will return a hash calculated using the Keccak-256 SHA3 algorithm.