Let Lighthouse wait a bit longer for FCP

[grgur]

Increased max FCP timeout in lighthouse to avoid known issues that occur when pages are taking a long time to paint. These projects are the ones that need good value from Gimbal 😄

Fixes #105

[akagr]

@grgur While 60 seconds should be generous enough for most projects, is there value in exposing that as gimbal config?

[grgur]

Good thinking. I think we should have a common interface for forwarding any Lighthouse-specific config to Lighthouse