Set up TravisCI deploy to k8s on successful build

[Sch3lp]

• [ ] Install kubectl on TravisCI
• [ ] Replace Heroku deployment with kubectl apply
• [ ] Do sed on deployment with latest docker image sha to update meta:label so kubernetes picks it up as a change.

sed -i "s|commithash|$CI_COMMIT_SHA|" ops/webapp/deployment.yaml
    - kubectl apply -f ops/webapp/deployment.yaml

In deployment.yaml there's then this:

apiVersion: apps/v1
kind: Deployment
metadata:
  name: effit-deployment
  labels:
    app: effit-challenge-webapp
spec:
  replicas: 1
  selector:
    matchLabels:
      app: effit-challenge-webapp
  template:
    metadata:
      labels:
        app: effit-challenge-webapp
        commit: commithash
      annotations:
        prometheus.io/path: "/actuator/prometheus"
        prometheus.io/port: "8082"
        prometheus.io/scrape: "true"
    spec:
      containers:
        - name: effit-app
          image: registry.gitlab.rotate-it.be/sch3lp/effit-challenge:latest
          imagePullPolicy: Always
          ports:
            - containerPort: 8080

And commithash will be replaced.