It turns page.size() and page.setSize() methods are slightly
confusing since there multiple different sizes (layout size,
content size, viewport size..)
This patch renames Page.{size,setSize} methods into
Page.{viewportSize,setViewportSize} methods to avoid confusion.
This patch:
- renames phantomjs folder into phantom_shim
- moves bin/puppeteer into a phantom_shim/runner.js and
merges the file with phantomjs/index.js
- removes "bin" field from the package.json - it is confusing
to have phantom shim installable