Merge pull request #230 from joekiller/fix_unsupported_metadata

raise NotImplementedError on unknown metadata path

moto/core/responses.py

@@ -158,4 +158,6 @@ def metadata_response(request, full_url, headers):
         result = 'default-role'
     elif path == 'iam/security-credentials/default-role':
         result = json.dumps(credentials)
+    else:
+        raise NotImplementedError("The {0} metadata path has not been implemented".format(path))
     return 200, headers, result