Update integration test helper

[craigspaeth]

It could be simpler and more helpful using a .env.test file and child.stdout.pipe process.stdout

e.g.

spawn = require("child_process").spawn
express = require "express"

# Stubbed API
@api = express()

# Spawns a child process with test .env.test variables
@startServer = (callback) =>
  return callback() if @child?
  @child = spawn "make", ["test-s"],
    customFds: [0, 1, 2]
    stdio: ["ipc"]
  @child.on "message", -> callback()
  @child.stdout.pipe process.stdout

# Closes the server child process, used in an `after` hook and on
# `process.exit` in case the test suite is interupted.
@closeServer = =>
  @child?.kill()
  @child = null

process.on "exit", @closeServer