Update e2e testing guide

[nikhita]

The doc https://github.com/kubernetes/community/blob/master/contributors/devel/sig-testing/e2e-tests.md is very stale and lots of portions need a re-write.

Ref: #2701 (comment)

/cc @BenTheElder @spiffxp @cjwagner

/sig testing
/area contributor-guide
/kind bug

[krzyzacy]

/milestone 2019
/cc

also contributors/devel/e2e-node-tests.md here
probably will do after a kubetest overhaul

[fejta-bot]

Issues go stale after 90d of inactivity.
Mark the issue as fresh with /remove-lifecycle stale.
Stale issues rot after an additional 30d of inactivity and eventually close.

If this issue is safe to close now please do so with /close.

Send feedback to sig-testing, kubernetes/test-infra and/or fejta.
/lifecycle stale

[nikhita]

/remove-lifecycle stale

…

On Mon 14 Jan, 2019, 12:28 AM fejta-bot, ***@***.***> wrote: Issues go stale after 90d of inactivity. Mark the issue as fresh with /remove-lifecycle stale. Stale issues rot after an additional 30d of inactivity and eventually close. If this issue is safe to close now please do so with /close. Send feedback to sig-testing, kubernetes/test-infra and/or fejta <https://github.com/fejta>. /lifecycle stale — You are receiving this because you authored the thread. Reply to this email directly, view it on GitHub <#2759 (comment)>, or mute the thread <https://github.com/notifications/unsubscribe-auth/APXA0OVhu8AMmfcXMlvQg0D1B7t9EXW2ks5vC4HsgaJpZM4XLd3X> .

[nikhita]

/kind documentation