<!--- Verify first that your issue is not already reported on GitHub -->
<!--- Also test if the latest release and devel branch are affected too -->
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##### SUMMARY

It is not possible to use k8s_scale due to missing key merge_type.

##### ISSUE TYPE
- Bug Report

##### COMPONENT NAME
k8s_scale

##### ANSIBLE VERSION
<!--- Paste verbatim output from "ansible --version" between quotes -->
```paste below
ansible 2.8.2
  config file = /Users/chbr/repos/work/components/helm/ansible.cfg
  configured module search path = ['/Users/chbr/.ansible/plugins/modules', '/usr/share/ansible/plugins/modules']
  ansible python module location = /usr/local/lib/python3.7/site-packages/ansible
  executable location = /usr/local/bin/ansible
  python version = 3.7.3 (default, Mar 27 2019, 09:23:15) [Clang 10.0.1 (clang-1001.0.46.3)]
```

##### CONFIGURATION
<!--- Paste verbatim output from "ansible-config dump --only-changed" between quotes -->
```paste below
```

##### OS / ENVIRONMENT
<!--- Provide all relevant information below, e.g. target OS versions, network device firmware, etc. -->

Client is macOS 10.14.4
Cluster is OKD 3.11

##### STEPS TO REPRODUCE

On a newly deployed OKD cluster I fired up a Tiller service successfully. But deleting it via the `k8s` module does not delete the pods because of some issue in Kubernetes API. So my attempted work around is to scale down the deployment before deleting it.

<!--- Paste example playbooks or commands between quotes below -->
```yaml
- name: Scale down Tiller
  k8s_scale:
    kind: Deployment
    name: tiller-deploy
    api_version: v1
    namespace: myproject
    replicas: 0
```

<!--- HINT: You can paste gist.github.com links for larger files -->

##### EXPECTED RESULTS
<!--- Describe what you expected to happen when running the steps above -->
I expect Ansible to succeed and the deployment to be scaled down to 0 replicas.

##### ACTUAL RESULTS
<!--- Describe what actually happened. If possible run with extra verbosity (-vvvv) -->

<!--- Paste verbatim command output between quotes -->
```paste below
/Users/chbr/.ansible/tmp/ansible-tmp-1562923350.045843-76777999244172/AnsiballZ_k8s_scale.py:18: DeprecationWarning: the imp module is deprecated in favour of importlib; see the module's documentation for alternative uses
  import imp
Traceback (most recent call last):
  File "/Users/chbr/.ansible/tmp/ansible-tmp-1562923350.045843-76777999244172/AnsiballZ_k8s_scale.py", line 114, in <module>
    _ansiballz_main()
  File "/Users/chbr/.ansible/tmp/ansible-tmp-1562923350.045843-76777999244172/AnsiballZ_k8s_scale.py", line 106, in _ansiballz_main
    invoke_module(zipped_mod, temp_path, ANSIBALLZ_PARAMS)
  File "/Users/chbr/.ansible/tmp/ansible-tmp-1562923350.045843-76777999244172/AnsiballZ_k8s_scale.py", line 49, in invoke_module
    imp.load_module('__main__', mod, module, MOD_DESC)
  File "/usr/local/Cellar/python/3.7.3/Frameworks/Python.framework/Versions/3.7/lib/python3.7/imp.py", line 234, in load_module
    return load_source(name, filename, file)
  File "/usr/local/Cellar/python/3.7.3/Frameworks/Python.framework/Versions/3.7/lib/python3.7/imp.py", line 169, in load_source
    module = _exec(spec, sys.modules[name])
  File "<frozen importlib._bootstrap>", line 630, in _exec
  File "<frozen importlib._bootstrap_external>", line 728, in exec_module
  File "<frozen importlib._bootstrap>", line 219, in _call_with_frames_removed
  File "/var/folders/d0/bmn8x1693sv_fcgb8kbyv4s40000gn/T/ansible_k8s_scale_payload_q4dt8qvw/__main__.py", line 129, in <module>
  File "/var/folders/d0/bmn8x1693sv_fcgb8kbyv4s40000gn/T/ansible_k8s_scale_payload_q4dt8qvw/__main__.py", line 125, in main
  File "/var/folders/d0/bmn8x1693sv_fcgb8kbyv4s40000gn/T/ansible_k8s_scale_payload_q4dt8qvw/ansible_k8s_scale_payload.zip/ansible/module_utils/k8s/raw.py", line 115, in __init__
KeyError: 'merge_type'
```

""" Create a stream of events for the object """
        w = None
        stream = None
        try:
            w = watch.Watch()
            w._api_client = self.client.client
            if namespace:
                stream = w.stream(resource.get, serialize=False, namespace=namespace, timeout_seconds=wait_time)
            else:
                stream = w.stream(resource.get, serialize=False, namespace=namespace, timeout_seconds=wait_time)
        except KubernetesException:
            pass
        return w, stream
    def _read_stream(self, resource, watcher, stream, name, replicas):