Fix CI #12
Description
- linking zmq fails under clang
json.hppsomehow isn't happy with gcc 4.9 (see also: support gcc 4.8.1 nlohmann/json#212, GCC 48 nlohmann/json#1257)
{{ message }}
json.hpp somehow isn't happy with gcc 4.9 (see also: support gcc 4.8.1 nlohmann/json#212, GCC 48 nlohmann/json#1257)