New CR workflow with GH issues: fetch ALL open issues

[tripu]

echidna/lib/transition-checker.js

Line 40 in fb5a7c4

per_page: 100 // TODO: get all the issues, not just the first 100

Do proper pagination.

cf #575

[plehegar]

I wouldn't expect the w3c/transitions to have over a 100 open issues at once. We don't accumulate more than 6/7 transition requests at a time. And for issues related to the transition requirements, we shouldn't accumulate more than 50 open issues at any time.