Fix PS command

[danbulant]

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When using docker-compose, it always skips the first container (because indexes are zero based).

The other commit is that docker-compose (at least v2.0.1) also sends the name of the container and the service name, which the current parser doesn't account for.

[Steveb-p]

As shown by the tests, this will break docker-compose 1.x usage. We will need to decide on an approach for this.

Probably a configuration option?

I don't really feel we can split codebase into two separate versions, as that would introduce more problems than solve (since there is no way of detecting which docker-compose version is installed during package installation).

[AlexZeitler]

I think providing something like a majorVersion option is the most appropriate way to solve this.