1.1.0

• Fix #132 - withFilter was previously always passing undefined as its first argument to the filterFn.
• Partially attempt to fix #143 - try to reduce occurrence of certain memory leaks with the built-in PubSubEngine implementation.
• Replaced eventEmitterAsyncIterator with default generic AsyncIterator named PubSubAsyncIterator. extends PubSubEngine automatically uses generic implementation. No breaking changes for those who continue to use implements PubSubEngine. See PR #78.