THRIFT-4571: Updated ZeroMQ examples to ZeroMQ version >= 3.0. (#1556)

* New style for Python is default now.
* Symbols were replaced in newer versions of ZeroMQ (>=3.0).
* Use Thrift's abstraction for `shared_ptr` instead of Boost.
* Symbols were replaced in Python as well.
diff --git a/contrib/zeromq/test-sender.cpp b/contrib/zeromq/test-sender.cpp
index 6b0eef1..8928db3 100644
--- a/contrib/zeromq/test-sender.cpp
+++ b/contrib/zeromq/test-sender.cpp
@@ -6,7 +6,7 @@
 #include "TZmqClient.h"
 #include "Storage.h"
 
-using boost::shared_ptr;
+using apache::thrift::stdcxx::shared_ptr;
 using apache::thrift::transport::TZmqClient;
 using apache::thrift::protocol::TBinaryProtocol;