Fixes unsorted dicts and sets in doctests

A few doctests were checking the values of dictionaries and sets
without sorting them in any way.  This was causing some of the
doctests to fail when the order inside the dictionary or set changed
and wasn't consistent.  Now all of the doctests check against sorted
values so the tests are consistent in their output every time.

Change-Id: I52b30327fb4acb3f1ee57ae14b611e988a43576a
Closes-Bug: 1347937

doc/source/arguments_and_results.rst

@@ -53,8 +53,8 @@ the task.
     ...     def execute(self, spam, eggs):
     ...         return spam + eggs
     ...
-    >>> MyTask().requires
-    set(['eggs', 'spam'])
+    >>> sorted(MyTask().requires)
+    ['eggs', 'spam']
 
 Inference from the method signature is the ''simplest'' way to specify task
 arguments. Optional arguments (with default values), and special arguments like

doc/source/inputs_and_outputs.rst

@@ -34,6 +34,7 @@ set of names of such values is available via ``provides`` property of the flow.
     from taskflow import task
     from taskflow.patterns import linear_flow
     from taskflow import engines
+    from pprint import pprint
 
 For example:
 
@@ -118,10 +119,11 @@ of the engine helpers (:py:func:`~taskflow.engines.helpers.run` or
    >>> flo = linear_flow.Flow("cat-dog")
    >>> flo.add(CatTalk(), DogTalk(provides="dog"))
    <taskflow.patterns.linear_flow.Flow object at 0x...>
-   >>> engines.run(flo, store={'meow': 'meow', 'woof': 'woof'})
+   >>> result = engines.run(flo, store={'meow': 'meow', 'woof': 'woof'})
    meow
    woof
-   {'meow': 'meow', 'woof': 'woof', 'dog': 'dog'}
+   >>> pprint(result)
+   {'dog': 'dog', 'meow': 'meow', 'woof': 'woof'}
 
 You can also directly interact with the engine storage layer to add additional
 values, note that if this route is used you can't use
@@ -154,8 +156,8 @@ For example:
    >>> eng.run()
    meow
    woof
-   >>> print(eng.storage.fetch_all())
-   {'meow': 'meow', 'woof': 'woof', 'dog': 'dog'}
+   >>> pprint(eng.storage.fetch_all())
+   {'dog': 'dog', 'meow': 'meow', 'woof': 'woof'}
    >>> print(eng.storage.fetch("dog"))
    dog