Re-implement openurlwithproxy.js example
Re-implement openurlwithproxy.js example

This patch adds example which illustrates running chromium with
proxy server.

brutalcrozt/puppeteer,michaelfward/puppeteer,puppeteer/puppeteer,ianchn/puppeteer,brutalcrozt/puppeteer,michaelfward/puppeteer,elisherer/puppeteer,puppeteer/puppeteer,elisherer/puppeteer,GoogleChrome/puppeteer,puppeteer/puppeteer,GoogleChrome/puppeteer,puppeteer/puppeteer,a1ph/puppeteer,ianchn/puppeteer,a1ph/puppeteer,GoogleChrome/puppeteer