Adds support for deploy: mode.
For example:
```yaml
version: "3"
services:
foo:
deploy:
resources:
mode: global
replicas: 6
image: redis
```
Will only generate replicas: 1 in Kubernetes pods as "global" limits
replicas to only one.
This does a major refactor on the compose.go functions as well as brings
in a new era of v3 support to Kompose.
Similar to how we utilize libcompose, we utilize docker/cli's "stack
deploy" code which has a built-in v3 parser. We convert the parsed
structure to our own and then convert it to Kubernetes/OpenShift
artifacts.
