Feature request: Async/Promise memoization

Currently only synchronous calls are supported in memoize function. Would it make sense to also add support or dedicated function for async/Promise memoization?

Caching promises instead of their final results can lead to potential memory leaks so having option of tool which prevents this by proper memoization could help in preventing this problem.

Sync implementation is pretty similar to basic async memoization so it could be easily adapted.