Default kubeconfig to None in chart

[t1bb4r]

#507 Introduced a small regression. It doesn't look like a breaking change, but the chart documentation does still specify that the default kube config is "None" and this is not the case in 1.2.0. While the default kubeconfig seems harmless it doesn't reflect what has happened pre 1.2.0 and what is currently in the README.md

This PR reverts to pre 1.2.0 kube.config.

In 1.2.0 the chart uses the config map by default, even when the documentation says it doesn't as shown in the diff below.
In my proposed change the config map is removed (#507) and everything else stays exactly the same as shown in second diff.

diff template1.1.0-yaml template1.2.0-yaml 
9c9
<     chart: helm-operator-1.1.0
---
>     chart: helm-operator-1.2.0
47c47
<     chart: helm-operator-1.1.0
---
>     chart: helm-operator-1.2.0
69c69
<     chart: helm-operator-1.1.0
---
>     chart: helm-operator-1.2.0
88c88
<     chart: helm-operator-1.1.0
---
>     chart: helm-operator-1.2.0
109c109
<     chart: helm-operator-1.1.0
---
>     chart: helm-operator-1.2.0
129a130,133
>       - name: config
>         configMap:
>           name: RELEASE-NAME-helm-operator-kube-config
>           defaultMode: 0600
159a164,166
>         - name: config
>           mountPath: /root/.kube
>           readOnly: true
164a172
>         - --kubeconfig=/root/.kube/config

diff template1.1.0-yaml template-proposed.yaml 
9c9
<     chart: helm-operator-1.1.0
---
>     chart: helm-operator-1.2.0
27,38d26
<     apiVersion: v1
<     clusters: []
<     contexts:
<     - context:
<         cluster: ""
<         namespace: default
<         user: ""
<       name: default
<     current-context: default
<     kind: Config
<     preferences: {}
<     users: []
47c35
<     chart: helm-operator-1.1.0
---
>     chart: helm-operator-1.2.0
69c57
<     chart: helm-operator-1.1.0
---
>     chart: helm-operator-1.2.0
88c76
<     chart: helm-operator-1.1.0
---
>     chart: helm-operator-1.2.0
109c97
<     chart: helm-operator-1.1.0
---
>     chart: helm-operator-1.2.0

templates were generated using helm template .