Solution: apply naming style

Solution: migrate to Unity

Solution: migrate to unity assertions

Solution: pass the flags to zmq_recv

Solution: extracted bind_loopback

Solution: Moved bind_loopback_ipv4 to testutil_unity to allow for reuse

Solution: migrate to unity, and split test cases

Solution: provide test_context and manage sockets of test_context via setup and teardown

Solution: migrate to unity