Run bosh CPI certification tests

[gberche-orange]

I ran into this repo which might help complement the test coverage for cloudstack cpi:

https://github.com/cloudfoundry-incubator/bosh-cpi-certification

Contributing cloudstack cpi to this repo will help bosh maintainers know when they'd break cloudstack.

See related similar exchanges with alicloud team for their cpi https://github.com/cloudfoundry/pmc-notes/blob/master/Bosh/2019-03-21-bosh.md

[psycofdj]

Thanks @gberche-orange, this is a great idea
We're keeping the issue open until we find time to integrate to this tool