Add failing fs.async.list spec.

spec/stdlib/fs-spec.coffee

@@ -0,0 +1,15 @@
+fs = require 'fs'
+
+describe "fs", ->
+  describe ".async", ->
+    describe ".list(directoryPath)", ->
+      directoryPath = nil
+      beforeEach -> directoryPath = require.resolve 'fixtures/file-finder-dir'
+
+      it "returns a promise that resolves to the contents of that directory", ->
+        waitsFor (complete) ->
+          promise = fs.async.list(directoryPath)
+          promise.done (result) ->
+            expect(result).toEqual fs.list(directoryPath)
+          promise.done complete
+