Flaky ipns-pubsub tests

[achingbrain]

These fail frequently in CI:

 1) ipns-pubsub
       should publish the received record to a go node and a js subscriber should receive it:
     Error: Could not find peer subscribing
      at /home/travis/build/ipfs/interop/test/ipns-pubsub.js:122:11
      at processTicksAndRejections (internal/process/task_queues.js:97:5)
      at async RetryOperation._fn (node_modules/p-retry/index.js:41:12)