* Add append_hash functionality to k8s module
append_hash adds a hash based on the contents of a ConfigMap
or Secret to the name - this enables immutable ConfigMaps and
Secrets.
* Provide k8s_config_resource_name plugin
The k8s_config_resource_name filter plugin provides a means of determining
the name of ConfigMaps and Secrets created with append_hash
* Add changelog fragment
* fix failing tests
* Update openshift version needed for append_hash
* Use a sensible default for k8s merge_type
The sensible default for merge_type is `['strategic-merge', 'merge'].
However, we can't make this the default default, as we need to support
users who are using openshift 0.6.0, where the merge_type parameter is
unsupported.
* Refactor k8s test suite for merge_type tests
Allow tests with pre-merge-type openshift and post-merge-type
openshift.