MongoDB Kubernetes Operator 0.8.0

Kubernetes Operator

Changes
- The Operator now uses the official MongoDB Community Server images.
  It is still possible to use the Docker Inc. images by altering the JSON configuration file:
```
      mongodb_image_name=mongo
      mongodb_image_repo_url=docker.io
```
  Alternatively, it is possible to the Operator environmental variables to:
```
      MONGODB_IMAGE=mongo
      MONGODB_REPO_URL=docker.io
```
  The upgrade process for the official MongoDB images is automatic when using the default settings provided by both,
  kubectl and Helm
  operator installation methods. Once the Operator boots up, it will replace image tags in the StatefulSets. If however,
  you're using customized deployments (by modifying MONGODB_IMAGE or MONGODB_REPO_URL environment variable in the Operator
  Deployment), please check if your settings are correct and if they are pointing to the right coordinates. The Operator
  still provides basic backwards compatibility with previous images (docker.io/mongo).
mongodb-readiness-hook and mongodb-version-upgrade-hook images are now rebuilt daily, incorporating updates to system packages and security fixes. The binaries are built only once during the release process and used without changes in daily rebuilt

All the images can be found in: