Problem: TestPushPullChanneler randomly fails (crash)
Problem: TestPushPullChanneler randomly fails (crash)

New czmq sockets are created concurrently when creating a channel.
This may lead to a crash when initializing the CZMQ context the first time:
src/zsys.c:179: zsys_init: Assertion `!s_process_ctx' failed.

To solve this concurrency issue, initialize the CZMQ context earlier in the main thread

indradhanush/goczmq,nbargnesi/goczmq