SKALE-1887 Add stubclient back

stubclient.cpp

+//
+// Created by kladko on 9/23/19.
+//
+
+#include <iostream>
+
+#include "stubclient.h"
+#include <jsonrpccpp/client/connectors/httpclient.h>
+
+using namespace jsonrpc;
+using namespace std;
+
+int init_client() {
+    HttpClient client("http://localhost:1025");
+    StubClient c(client, JSONRPC_CLIENT_V2);
+
+    Json::Value params;
+
+    try {
+        cout << c.generateECDSAKey() << endl;
+    } catch (JsonRpcException &e) {
+        cerr << e.what() << endl;
+    }
+    return 0;
+}