message: correct a typing of web3 generator
  fix
diff: @@ -39,7 +39,7 @@ export function codegen(contract: Contract) {
  allEvents: (
  options?: {
  filter?: object;
  - fromBlock?: Block;
  + fromBlock?: number | string;
  topics?: (null|string)[];
  },
  cb?: Callback<EventLog>
  @@ -90,7 +90,7 @@ function generateEvents(event: EventDeclaration) {
  ${event.name}(
  options?: {
  filter?: object;
  - fromBlock?: Block;
  + fromBlock?: number | string;
  topics?: (null|string)[];
  },
  cb?: Callback<EventLog>): EventEmitter;
  