Added protection to make sure that multiple instances will never run in parallel
Moved the watchdog startup to right before the first test executes to prevent a spiral where watchdogs keep spawning new instances.
Added messaging to the install flow to make it easier to identify which installer fails
Fixed #74 - Added another navigation to a local blank page during the chrome startup to make the ruler displayed by dev tools go away.

Unfortunately it is a bit timing sensitive and not 100% deterministic so hopefully this fixes all cases (otherwise may need to increase the startup timer).
wptdriver 124