Exclude browser specs from Jest migration
This will (in theory) allow us to reach 100% funniness, by excluding tests that must run in a real browser.
I'm not sure what the plan is with _browser_spec.js
tests. If we never move them to Jest, then we shouldn't count them here. If we will, then perhaps it's best not to exclude them (i.e., close this MR).
Edited by Mark Florian