Add go support to RocketUpgrade.thrift

Summary: Want to be able to use it in Go code downstream.

Reviewed By: leoleovich

Differential Revision: D70358294

fbshipit-source-id: b9ce4c947ae543337d53b7f31970ebfdbf302b59

thrift/lib/thrift/RocketUpgrade.thrift

@@ -16,6 +16,7 @@
 
 namespace cpp2 apache.thrift
 namespace py3 thrift.lib.thrift
+namespace go 'github.com/facebook/fbthrift/thrift/lib/thrift/rocket_upgrade'
 
 /**
  * This interface should be used by the clients that want to attempt upgrading