We don't support it and v3 shipped without including puppeteer-web in the browser. People are welcome to manually use Browserify to try to get Puppeteer running in a browser but it ultimately isn't our primary focus right now.
Getting puppeteer-core able to run in a browser is something we'll be looking at in the future so we'll revisit this soon.
Our CI build has been incredibly flaky across all three of our current CIs:
* Appveyor: Chromium + Windows
* Travis: Firefox + Linux, Chromium + Linux
* Cirrus: Chromium + Linux, Chromium + Mac
Legitimate issues and errors have been missed because it's expected that the CI is red and therefore it's not seen as an issue when a PR's build fails.
We should have a build that covers the full combo of browsers and operating systems but it's more important to have a consistent, reliable green build where failures are genuine. So this commit strips our CI back to Chromium on Linux on Travis, and nothing more. Once this is stable we will expand out into more operating systems and bring back Firefox, too.
