initial worker plugin
ake it work
add Sauce-Connect license details
begin npm start code and check for server socket readyness
now depends on request
getting pretty saucey
tidy;
parameterize http server port
clarity
read sauce creds from env (just for now)
properly detect for sauce connector being ready for tests
better signals
we cannot use `npm start` directly because it turns out that will fork a subprocess in which to run
the start script.

because Strider needs to know the PID of the server process in order to kill it later, this doesn't work.

instead, we parse the package.json ourselves and read the value of the start script. then we execute
that process directly in order that we know the PID.

this means we can always kill the server process.
tidy & better comments
spacing
error handling; line break;
moar commentz
replace custom prepare function with "npm install" string - cuts out a bunch of code
more descriptive constant names
use npmCmd wrapper from context.
use a constant for http check interval.