fix release prep for gh actions

[brycahta]

Issue #, if available:

• Last release failed in 2 areas:
  • the chart version was not incremented in the eks-charts PR
  • gh actions errored out when trying to publish version updates to ReadMe (post release)
    • one reason being previousVersion == latestVersion

Description of changes:

• Updated make release-prep-X to increment Chart.yaml version as part of the Release-Prep PR
• If previousVersion == latestVersion, then fetch previous-previous version
• Add git config for ec2-bot
• Update sed replacement to work with Mac and Linux
• Circumvent pr-publish-prompt when updating ReadMe only (triggered by bot and considered post-release)
• Exit gracefully when no file changes required

By submitting this pull request, I confirm that my contribution is made under the terms of the Apache 2.0 license.

[bwagner5]

LGTM

[bwagner5]

e2e k8s 1.17 failure is just due to ec2-metadata-mock docker image pull issue which should be fixed with aws/amazon-ec2-metadata-mock#116

2021/01/06 23:08:21 ??? There was a problem monitoring for events error="There was a problem checking for spot ITNs: Unable to parse metadata response: Unable to get a response from IMDS: Get \"http://amazon-ec2-metadata-mock-service.default.svc.cluster.local:1355/latest/meta-data/spot/instance-action\": dial tcp 10.96.185.117:1355: connect: connection refused" event_type=SPOT_ITN
2021/01/06 23:08:21 ??? Trying to get token from IMDSv2
2021/01/06 23:08:22 ??? Unable to retrieve an IMDSv2 token, continuing with IMDSv1 error="Put \"http://amazon-ec2-metadata-mock-service.default.svc.cluster.local:1355/latest/api/token\": dial tcp 10.96.185.117:1355: connect: connection refused"
2021/01/06 23:08:23 ??? Request failed. Attempts remaining: 1
2021/01/06 23:08:23 ??? Sleep for 5.344459842s seconds
2021/01/06 23:08:23 ??? Request failed. Attempts remaining: 2
2021/01/06 23:08:23 ??? Sleep for 2.151964631s seconds
2021/01/06 23:08:26 ??? Request failed. Attempts remaining: 1
2021/01/06 23:08:26 ??? Sleep for 5.985257801s seconds
2021/01/06 23:08:29 ??? There was a problem monitoring for events error="Unable to parse metadata response: Unable to parse metadata response: Unable to get a response from IMDS: Get \"http://amazon-ec2-metadata-mock-service.default.svc.cluster.local:1355/latest/meta-data/events/maintenance/scheduled\": dial tcp 10.96.185.117:1355: connect: connection refused" event_type=SCHEDULED_EVENT
2021/01/06 23:08:29 ??? Trying to get token from IMDSv2
2021/01/06 23:08:30 ??? Unable to retrieve an IMDSv2 token, continuing with IMDSv1 error="Put \"http://amazon-ec2-metadata-mock-service.default.svc.cluster.local:1355/latest/api/token\": dial tcp 10.96.185.117:1355: connect: connection refused"
2021/01/06 23:08:31 ??? Request failed. Attempts remaining: 2
2021/01/06 23:08:31 ??? Sleep for 2.442480269s seconds
⏰ Took 1491sec
❌ NTH Integration Test FAILED nth-test-cebb2aa4! ❌
🥑 Deleting k8s cluster using "kind"
Deleting cluster "nth-test-cebb2aa4" ...

[brycahta]

Testing on separate repo worked 🥳

https://github.com/brycahta/nth-test/runs/1663510030?check_suite_focus=true
https://github.com/brycahta/nth-test/pull/4