Use compose-go + improvements (#9)

Use compose-go https://github.com/compose-spec/compose-go  to make Katenary parsing compose file the official way.
Add labels:
- `volume-from` (with `same-pod`) to avoid volume repetition
- `ignore` to ignore a service
- `mapenv` (replaces the `env-to-service`) to map environment to helm variable (as a template string)
- `secret-vars` declares variables as secret values

More:
- Now, environment (as secret vars) are set in values.yaml
- Ingress has got annotations in values.yaml
- Probes (liveness probe) are improved
- fixed code to optimize
- many others fixes about path, bad volume check, refactorisation, tests...

generator/writers/utils.go

@@ -1,6 +1,6 @@
 package writers
 
-// IndentSize set the indentation size for yaml output.
+// IndentSize set the indentation size for yaml output. Could ba changed by command line argument.
 var IndentSize = 2
 
 // CountSpaces returns the number of spaces from the begining of the line.