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-receiver.cpp b/contrib/zeromq/test-receiver.cpp
index 8fe69da..60791ac 100644
--- a/contrib/zeromq/test-receiver.cpp
+++ b/contrib/zeromq/test-receiver.cpp
@@ -2,7 +2,7 @@
 #include "TZmqServer.h"
 #include "Storage.h"
 
-using boost::shared_ptr;
+using apache::thrift::stdcxx::shared_ptr;
 using apache::thrift::TProcessor;
 using apache::thrift::server::TZmqServer;
 using apache::thrift::server::TZmqMultiServer;