title: Poltergeist toggle proxy during test runtime
body: <p>We are just migrating from capybara-webkit to Poltergeist. Previously we did use capybara-webkit with <a href="https://github.com/oesmith/puffing-billy" rel="nofollow" title="puffing billy proxy">puffing billy</a> as you can see here:</p>
  
  <pre><code>def use_proxy_with_vcr cassettes_name = nil, cassettes_options = {}
    page.driver.browser.set_proxy(:host =&gt; Billy.proxy.host, :port =&gt; Billy.proxy.port)
    page.driver.browser.ignore_ssl_errors
    Billy.proxy.strategy.use_cassette cassettes_name, cassettes_options
    yield
    Billy.proxy.strategy.reset
    page.driver.browser.clear_proxy
  end
  </code></pre>
  
  <p>This happens on runtime and <strong>I would like to do the same thing with Poltergeist</strong>. I realized one could set a proxy and ignore ssl errors by passing CLI options through capybara driver setup with phantomjs_options (<a href="https://github.com/jonleighton/poltergeist#customization" rel="nofollow">https://github.com/jonleighton/poltergeist#customization</a>).</p>
  
  <p>Is it possible to enable/disable proxy and ssl errors during runtime? If yes how?</p>