Added sort_keys default to True into to_json method.

This is very usefull both for unit testing and for readability.

idea/base.py

@@ -346,4 +346,5 @@ class IdeaBase(typedcols.TypedDict):
             raise ValueError(o)
 
     def to_json(self, *args, **kwargs):
+        kwargs.setdefault('sort_keys', True)
         return json.dumps(self, default=self.json_default, *args, **kwargs)

test_idea.py

@@ -79,13 +79,13 @@ class TestIdea(unittest.TestCase):
     def testLiteIdea(self):
         idea = lite.Idea(raw_idea)
         orig = json.dumps(raw_idea, indent=4, sort_keys=True)
-        new = idea.to_json(indent=4, sort_keys=True)
+        new = idea.to_json(indent=4)
         self.assertEqual(orig, new, "\n".join([l for l in difflib.context_diff(orig.split("\n"), new.split("\n"))]))
 
     def testValidIdea(self):
         idea = valid.Idea(raw_idea)
         orig = json.dumps(raw_idea, indent=4, sort_keys=True)
-        new = idea.to_json(indent=4, sort_keys=True)
+        new = idea.to_json(indent=4)
         self.assertEqual(orig, new, "\n".join([l for l in difflib.context_diff(orig.split("\n"), new.split("\n"))]))