chore(fixes): Unwrap yaml before converting and fix volume name variable

2 fixes:

- the first problem to resolve is that some volume names can have "-" in
the name. We now replace them by "_"
- the second problem is that k8s.io library truncates the lines and so
we cannot split the files by lines. We now "unwrap" the result.

TODO: globalize the `yaml.Marshal()` code to our own specific function

generator/generator.go

@@ -271,6 +271,7 @@ func buildVolumes(service types.ServiceConfig, chart *HelmChart, deployments map
 		}
 		switch v.Type {
 		case "volume":
+			v.Source = strings.ReplaceAll(v.Source, "-", "_")
 			pvc := NewVolumeClaim(service, v.Source, appName)
 
 			// if the service is integrated in another deployment, we need to add the volume