Fix integration tests for upgrade flag

[paologallinaharbur]

What this PR does / why we need it:
It fixes:

• the integration test "change immutable deployment.spec.selector field". Since the selector was missing from the manifest the upgrade tests was always failing causing a false positive. This is because the required fields changed in apps/v1 and selector were not added by Don't create provided namespace #205

The error always showing before the upgrade was:

missing required field "selector" in io.k8s.api.apps.v1.DeploymentSpec

It adds:

• integration tests to avoid regression of FIX: it should upgrade to new version instead of the old one #434. Basically two simple deployment manifests with the second one adding a different selector. The tests differ from the other one since the different selector belongs to a different chart/chartVersion

[cpanato]

lgtm
thanks!

[paologallinaharbur]

@davidkarlsen do you know if we can have a new release? or maybe you are currently in the process of releasing it already

[davidkarlsen]

@paologallinaharbur I'll see if I can get to it soon.

[cpanato]

@davidkarlsen i will review the repo tomorrow (27/july/2022) and prepare the release, maybe we need to bump a few things

[cpanato]

release v3.7.0 is out https://github.com/helm/chart-testing/releases/tag/v3.7.0