Fix return types of asyncReduce, asyncSome, asyncEvery (again) (#101)
Fix return types of asyncReduce, asyncSome, asyncEvery (again) (#101)

* changed function argument to be optionally asynchronous. amended tests and documentation

* Update type definition to match https://github.com/sithmel/iter-tools/pull/96

* Fix return types of asyncReduce, asyncSome, asyncEvery

* Then: They return bare value (synchronously)
* Now: They return promises

sithmel/iter-tools,sithmel/iter-tools