add zuul support for easier browser testing

To run tests in a local browser:
zuul --local 8080 -- test/index.js

To run tests in the cloud via saucelabs:
zuul -- test/index.js
add test support server

Allows for tests to actually make connections to a backend.
test: close socket connection once test done
travis: quote all node versions

unquoted 0.10 changes to 0.1 which is not what you really want
travis: add encrypted saucelabs env vars
update zuul version
run zuul tests after node tests
Merge pull request #210 from defunctzombie/zuul

browser and cloud testing via zuul