validation: should support `apis` under `packages`

[shazron]

aio-cli-lib-app-config/schema/app.config.yaml.schema.json

Line 116 in fd1dfac

"actions": { "$ref": "#/definitions/actions" }

https://github.com/apache/openwhisk-wskdeploy/blob/master/specification/html/spec_apis.md

[aiojbot]

JIRA issue created: https://jira.corp.adobe.com/browse/ACNA-3755