Allow unicode YAML dump with UnicodeYAMLRenderer

Fixes #1519

rest_framework/renderers.py

@@ -193,6 +193,7 @@ class YAMLRenderer(BaseRenderer):
     format = 'yaml'
     encoder = encoders.SafeDumper
     charset = 'utf-8'
+    ensure_ascii = True
 
     def render(self, data, accepted_media_type=None, renderer_context=None):
         """
@@ -203,7 +204,15 @@ class YAMLRenderer(BaseRenderer):
         if data is None:
             return ''
 
-        return yaml.dump(data, stream=None, encoding=self.charset, Dumper=self.encoder)
+        return yaml.dump(data, stream=None, encoding=self.charset, Dumper=self.encoder, allow_unicode=not self.ensure_ascii)
+
+
+class UnicodeYAMLRenderer(YAMLRenderer):
+    """
+    Renderer which serializes to YAML.
+    Does *not* apply character escaping for non-ascii characters.
+    """
+    ensure_ascii = False
 
 
 class TemplateHTMLRenderer(BaseRenderer):