CHANGELOG.md: Adding info about new locations for base images
### Changed
+- The official images for the Ansible and Helm operators have moved! Travis now builds, tags, and pushes operator base images during CI ([#832](https://github.com/operator-framework/operator-sdk/pull/832)).
+ - [quay.io/operator-framework/ansible-operator](https://quay.io/repository/operator-framework/ansible-operator)
+ - [quay.io/operator-framework/helm-operator](https://quay.io/repository/operator-framework/helm-operator)
+
### Deprecated
### Removed
