add mapstructure
diff --git a/third_party/mitchellh/mapstructure/README.google b/third_party/mitchellh/mapstructure/README.google
new file mode 100644
index 0000000..32696f8
--- /dev/null
+++ b/third_party/mitchellh/mapstructure/README.google
@@ -0,0 +1,3 @@
+mapstructure is a library for doing things with Go maps.
+
+URL: https://github.com/mitchellh/mapstructure.git