v2.1.0 release

This a new client and relayer release.

This new version is fully compatible with previous versions (that is, newer client can use older relayers, and vice-versa)

Client Changes

• We try to make creation simpler. a relayer is now created with a helper function:

   const gsnProvider = await RelayProvider
      .newProvider( provider,  { paymasterAddress: ..., }  )
      .init()

• the resolveConfigurationGSN,configureGSN methods are now removed completely from the API, as they became internal methods of the relay client.
• logger configuration are packed into inner structure. so to set logs to error only, you need to specify:
  loggerConfiguration: {logLevel: 'error'},
• loggerURL was added in previous release. now it is moved into the loggerConfiguration block.

Relay modifications (note that these items were reported on the unpublished 2.0.3 relay version)

• gasPriceOracle - relayer can use an external gas-price oracle, instead of relying on the Node's getGasPrice(). See #526
• support loggerUrl (like the client) to redirect logs to a centralized logger, for trouble-shooting.
• Several security enhancements:
  • Paymaster reputation mechanism
  • Improved boosting mechanism (after gas-price fluctuations):

Contracts

There are no contract changes. the new client and relayers are fully compatible with the deployed contacts (and also previous relayers/clients)