Feature/redis (#23)

* Fix warning

* (cmake) add a warning about 32/64 conversion problems.

* simple redis clients

* can publish to redis

* redis subscribe

* display messages received per second

* verbose flag

* (cmake) use clang only compile option -Wshorten-64-to-32 when compiling with clang

ws/IXRedisClient.h

@@ -0,0 +1,36 @@
+/*
+ *  IXRedisClient.h
+ *  Author: Benjamin Sergeant
+ *  Copyright (c) 2019 Machine Zone, Inc. All rights reserved.
+ */
+
+#pragma once
+
+#include <memory>
+#include <functional>
+
+namespace ix
+{
+    class Socket;
+
+    class RedisClient {
+    public:
+        using OnRedisSubscribeCallback = std::function<void(const std::string&)>;
+
+        RedisClient() = default;
+        ~RedisClient() = default;
+
+        bool connect(const std::string& hostname,
+                     int port);
+
+        bool publish(const std::string& channel,
+                     const std::string& message);
+
+        bool subscribe(const std::string& channel,
+                       const OnRedisSubscribeCallback& callback);
+
+    private:
+        std::shared_ptr<Socket> _socket;
+    };
+}
+