ci: integration test with hsd (big fix 4/4)

[pinheadmz]

Refactored out of bloated #76

Sets up a CI test for end to end integration:

• install nodejs, hsd, bmocha
• instantiate hsd full node, add blocks, win auctions, fill Urkel with DNS records
• spawn hnsd (freshly built by previous CI step)
• connect hnsd to hsd
• make DNS requests to hnsd using a stub resolver in bns

These tests SHOULD all fail right now, because they were written to cover #83 #84 and #86. Once those are merged, I'll rebase this and we should see it all pass.

TODO:

• document how to run the test
• make the test easier to run from root directory with one command (?)
• on CI maybe install bmocha globally and clean this up: ./node_modules/bmocha/bin/bmocha --reporter spec hnsd-integration-test.js