Merge branch 'development' into orderWatcher

* development:
  0.23.0
  Update CHANGELOG
  Fix amounts in tests one last time. Now that we updated the testRPC snapshot, this should no longer be mismatched between CI and locally
  Update testRPC snapshot used by CircleCi
  Push unsubscribe to the base class rather than super
  Check for null rather than undefined
  Removed nits
  Test case was error then unsubscribe
  Clean up subscription state.
  Fix unhandled promise rejection error on subscriptions

# Conflicts:
#	src/types.ts
#	test/exchange_wrapper_test.ts
#	test/token_wrapper_test.ts

1 files changed, 2 insertions, 2 deletions

diff --git a/src/types.ts b/src/types.ts
index a366fc31e..09b611019 100644
--- a/src/types.ts
+++ b/src/types.ts
@@ -42,8 +42,8 @@ export type OrderValues = [BigNumber, BigNumber, BigNumber,
 export type LogEvent = Web3.LogEntryEvent;
 export type DecodedLogEvent<ArgsType> = Web3.DecodedLogEntryEvent<ArgsType>;
 
-export type EventCallbackAsync<ArgsType> = (log: DecodedLogEvent<ArgsType>) => Promise<void>;
-export type EventCallbackSync<ArgsType> = (log: DecodedLogEvent<ArgsType>) => void;
+export type EventCallbackAsync<ArgsType> = (err: null|Error, log?: DecodedLogEvent<ArgsType>) => Promise<void>;
+export type EventCallbackSync<ArgsType> = (err: null|Error, log?: DecodedLogEvent<ArgsType>) => void;
 export type EventCallback<ArgsType> = EventCallbackSync<ArgsType>|EventCallbackAsync<ArgsType>;
 
 export type EventWatcherCallbackSync = (log: LogEvent) => void;