fix typo in examples/tests/nightwatch.js

Test is hitting _nightwatchjs.org_ rather than _google.com_.
Merge pull request #227 from davidlinse/patch-1

fix typo in examples/tests/nightwatch.js
refactor(protocol): support '/maximize' protocol
refactor(client-commands): add 'maximizeWindow' command
docs(api): add documentation to protocol and client
test(client-commands): test maximizeWindow command