Handle empty YAML manifests

[viglesiasce]

When using helm template to generate your base resources, there may be times when a resource is empty due to the way templating works in upstream charts. We should ignore empty manifests. Here is an example:

---
# Only a comment exists in this block
---
apiVersion: extensions/v1beta1
kind: Deployment
metadata:
  name: ci-jenkins
spec:
  template:
    spec:
      containers:
        - name: ci-jenkins
          image: jenkins/jenkins:lts

The error returned is:

$  kustomize buildError: loadResMapFromBasesAndResources: rawResources failed to read Resources: YAML file [/home/viglesias/git/kustomize-jenkins/charts/stable/my-jenkins/jenkins-base.yaml] encounters a format error.
error unmarshaling JSON: Object 'Kind' is missing in 'null'

For a example:

git clone https://github.com/kubernetes/charts.git
cd charts
helm template stable/jenkins

[zabio3]

I was on the same problem.
The problem was solved by deleting "---" unique to yaml. (Perhaps it seems that json parsing can not be done if there is "---".)