Adding json serializer

vcr/serializers/yamlserializer.py

@@ -0,0 +1,24 @@
+import yaml
+
+# Use the libYAML versions if possible
+try:
+    from yaml import CLoader as Loader, CDumper as Dumper
+except ImportError:
+    from yaml import Loader, Dumper
+
+
+class YamlSerializer(object):
+    @classmethod
+    def load(cls, cassette_path):
+        data = yaml.load(open(cassette_path), Loader=Loader)
+        requests = [r['request'] for r in data]
+        responses = [r['response'] for r in data]
+        return requests, responses
+
+    @classmethod
+    def dumps(cls, requests, responses):
+        data = ([{
+            'request': request,
+            'response': response,
+        } for request, response in zip(requests, responses)])
+        return yaml.dump(data, Dumper=Dumper)