Automated cherry pick of #7925: Extract the list of instance groups earlier in validation #8039: Vendor github.com/stretchr/testify/require #8159: Determine node role from instancegroup spec #8600: Fail cluster validation if a master missing

[johngmyers]

Cherry pick of #7925 #8039 #8159 #8600 on release-1.17.

#7925: Extract the list of instance groups earlier in validation
#8039: Vendor github.com/stretchr/testify/require
#8159: Determine node role from instancegroup spec
#8600: Fail cluster validation if a master missing

For details on the cherry pick process, see the cherry pick requests page.

[rifelpet]

/retest

[johngmyers]

/retest

[johngmyers]

/retest

[rifelpet]

/lgtm
/approve

[k8s-ci-robot]

[APPROVALNOTIFIER] This PR is APPROVED

This pull-request has been approved by: johngmyers, rifelpet

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[k8s-ci-robot]

@johngmyers: The following test failed, say /retest to rerun all failed tests:

Test name	Commit	Details	Rerun command
pull-kops-e2e-kubernetes-aws-1-17	eea95d6	link	/test pull-kops-e2e-kubernetes-aws-1-17

Full PR test history. Your PR dashboard. Please help us cut down on flakes by linking to an open issue when you hit one in your PR.

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[k8s-ci-robot]

@johngmyers: The following test failed, say /retest to rerun all failed tests:

Test name	Commit	Details	Rerun command
pull-kops-e2e-kubernetes-aws-1-17	eea95d6	link	/test pull-kops-e2e-kubernetes-aws-1-17

Full PR test history. Your PR dashboard. Please help us cut down on flakes by linking to an open issue when you hit one in your PR.

Instructions for interacting with me using PR comments are available here. If you have questions or suggestions related to my behavior, please file an issue against the kubernetes/test-infra repository. I understand the commands that are listed here.