Realized that the real underlying problem with the Future.merge(_:) w…

…as a deadlock because the zipping and resolving were happening from the same thread and blocking one another.

Sources/Propagate/PromiseAndFuture/Future+Combine.swift

@@ -13,12 +13,13 @@ public extension Future {
  - returns: A future where the success value is an array of the success values from the array of promises, and the error
  is whichever error happened first.
  */
- static func merge(_ futures: [Future<T, E>]) -> Future<[T], E> {
- let promise = Promise<[T], E>()
+ static func merge(_ futures: [Future<T,E>]) -> Future<[T],E> {
+ let promise = Promise<[T],E>()
+ let queue = DispatchQueue(label: "\(Future<T,E>.self) Merge Queue")
 
  futures.forEach { future in
  future.finally { (_) in
- promise.future.lockQueue.async {
+ queue.async {
  guard promise.future.isComplete == false else {
  return
  }