Merge branch '18-http-client' into 'master'

[18] grpc server and Rest API http client architecture

See merge request !92

cpp/tests/util/protobuf.hh

+#ifndef __VEREIGN_TEST_UTIL_PROTOBUF_HH
+#define __VEREIGN_TEST_UTIL_PROTOBUF_HH
+
+#include <string>
+#include <google/protobuf/message.h>
+
+namespace vereign {
+namespace test {
+
+std::string ProtobufToJson(const google::protobuf::Message& msg);
+
+} // namespace vereign
+} // namespace test
+
+#endif // __VEREIGN_TEST_UTIL_PROTOBUF_HH