Add canary instance step test

[Samze]

What is this change about?

Adds test for Canary steps.

Please provide contextual information.

• CAPI change: Add Canary steps cloud_controller_ng#4219
• CF CLI change: [v8] Allow users to push apps using a weighted canary deployment #3386 cli#3390

What version of cf-deployment have you run this cf-acceptance-test change against?

• todo

Please check all that apply for this PR:

• introduces a new test --- Are you sure everyone should be running this test?
• changes an existing test
• requires an update to a CATs integration-config

Did you update the README as appropriate for this change?

• YES
• N/A

If you are introducing a new acceptance test, what is your rationale for including it CATs rather than your own acceptance test suite?

Integration of CF CLI and CAPI.

How many more (or fewer) seconds of runtime will this change introduce to CATs?

~2mins

What is the level of urgency for publishing this change?

• Urgent - unblocks current or future work
• Slightly Less than Urgent

[a-b]

LGTM