message: Types fixes/cleanup
diff: import { Argv } from 'yargs'
  import { database, logging, stateChannels } from '@graphprotocol/common-ts'
  -import { EventPayloads, EventNames, toBN, ConditionalTransferTypes } from '@connext/types'
  +import { EventPayloads, EventNames, toBN, ConditionalTransferTypes, ResolveSignedTransferParameters } from '@connext/types'
  import { formatEther, hexlify, randomBytes, solidityKeccak256 } from 'ethers/utils'
  import { AddressZero } from 'ethers/constants'
  import express from 'express'
  @@ -8,7 +8,7 @@ import morgan from 'morgan'
  import { Stream } from 'stream'
  import { utils, Wallet } from 'ethers'
  import { signChannelMessage } from '@connext/crypto'
  -// import { PublicParams } from '@connext/types' TODO: why???
  +import { SignedTransferParameters } from '@connext/types'
  const delay = (time: number) => new Promise(res => setTimeout(res, time))
  @@ -114,8 +114,13 @@ export default {
  const amount = toBN(eventData.amount)
  let formattedAmount = formatEther(amount)
  + if (!eventData.sender) {
  + logger.error(`Sender not specified, cannot send payment back`)
  + return
  + }
  +
  logger.info(
  - `Received payment ${eventData.paymentId} (${formattedAmount} ETH) from ${eventData.meta.sender}, unlocking with key from ${wallet.address}...`,
  + `Received payment ${eventData.paymentId} (${formattedAmount} ETH) from ${eventData.sender}, unlocking with key from ${wallet.address}...`,
  )
  const data = hexlify(randomBytes(32))
  @@ -129,7 +134,7 @@ export default {
  paymentId: eventData.paymentId,
  data,
  signature,
  - } as any) // TODO: fix
  + } as ResolveSignedTransferParameters) // TODO: fix
  logger.info(
  `Unlocked payment ${eventData.paymentId} for (${formattedAmount} ETH)`,
  @@ -138,18 +143,18 @@ export default {
  await delay(1000)
  try {
  - logger.info(`Send ${formattedAmount} ETH back to ${eventData.meta.sender}`)
  + logger.info(`Send ${formattedAmount} ETH back to ${eventData.sender}`)
  let response = await client.transfer({
  amount,
  - recipient: eventData.meta.sender,
  + recipient: eventData.sender,
  assetId: AddressZero,
  })
  logger.info(
  - `${formattedAmount} ETH sent back to ${eventData.meta.sender} via payment ${response.paymentId}`,
  + `${formattedAmount} ETH sent back to ${eventData.sender} via payment ${response.paymentId}`,
  )
  } catch (e) {
  logger.error(
  - `Failed to send payment back to ${eventData.meta.sender}: ${e.message}`,
  + `Failed to send payment back to ${eventData.sender}: ${e.message}`,
  )
  }
  },
  