This patch:
- adds experimental "transport" option to pptr.connect
- uses "transport" option to make sure Puppeteer-Web works with
Target.exposeDevToolsProtocol
Drive-by: add `browser.target()` to access browser target.
This patch:
- adds "browser" field to the package.json with default
bundling options.
- introduces "bundle" and "unit-bundle" commands to
create bundle and test bundle
- starts running bundle tests on Travis Node 8 bots
Fixes#2374.
