Fix issues with a recent refactoring

jedi/evaluate/__init__.py

@@ -360,7 +360,7 @@ class Evaluator(object):
             scope_node = parent_scope(node)
         return from_scope_node(scope_node, is_nested=True, node_is_object=node_is_object)
 
-    def parse_and_get_code(self, code, path, **kwargs):
+    def parse_and_get_code(self, code=None, path=None, **kwargs):
         if self.allow_different_encoding:
             if code is None:
                 with open(path, 'rb') as f: