Add 'rodney connect HOST:PORT' to debug already-running chrome

[pnf]

For complicated reasons, I often need to run my agent and chrome on different hosts, and/or start chrome manually.

[simonw]

Tested locally -had to start a new Chrome like this:

/Applications/Google\ Chrome.app/Contents/MacOS/Google\ Chrome --remote-debugging-port=9222 --no-first-run --no-default-browser-check
  --user-data-dir=/tmp/chrome-debug-profile

Then this worked:

./rodney connect localhost:9222
./rodney status
./rodney open https://example.com
./rodney url
./rodney title

Thanks!