Lighthouse CI integration

[localnerve]

Integrate lighthouse into CI and fail build on threshold problems.

[addyosmani]

Do you have a feel for how well the current version in master does when tested against Lighthouse? For React projects in particular, you might find it useful to test against the branch with TTI support over here too: GoogleChrome/lighthouse#450

[localnerve]

I ran it about a month ago (~6/12) and fixed everything at that time until it was 100%.

Updates

• Here's a run of lighthouse 1.0.0 against master (pwa-stage) from 20160715
• Here's a WPT run (150ms RTT 3G) from 20160716, and shows DOMInteractive (closest I have to a TTI benchmark right now)

For anyone reading this later, items Lighthouse pointed out to me were extremely insightful/useful - stuff I probably wouldn't have caught until much later:

1. Allows non-https requests (A CloudFlare config update for this project)
2. WCAG contrast issues

A super tool so far - THANK YOU (all).

I can't wait to be able to check this automatically when I push changes to master. That will really be great. Not so sure about setup for Travis though - In the past, Chrome has been a little tricky to setup and maintain.

Any examples of setting up Lighthouse for CI (Chrome setup, etc)?

Anyways, thanks for the info, I'll be sure to checkout the TTI support branch.

[localnerve]

@addyosmani Is the TTI branch supposed to be runnable using the instructions + "develop instructions section" from GoogleChrome/lighthouse readme? I ran into a dep issue.
Repeat of this: GoogleChrome/lighthouse#503