kv-cp: add configMapName value to use your own configmap

[rptaylor]

This adds on to #48 and allows custom configmaps of IP pools to be used, which you can create and manage yourself.

• add .Values.configMapName, if defined your own custom configmap will be used
• cosmetic change to configmap name for templating simplicity , no functional impact

[rptaylor]

Test with values:

configMapName: kube-vip-address-pools

result:

I1030 16:20:51.342379       1 provider.go:86] Watching configMap for pool config with name: 'kube-vip-address-pools', namespace: 'kube-
vip'   

Another test using default config:

cm:
  data:
    cidr-default: 192.168.0.200/29

Then it uses the auto-generated configmap:

I1030 16:26:30.248381       1 provider.go:86] Watching configMap for pool config with name: 'kube-vip-cloud-provider', namespace: 'kube
-vip' 

[rptaylor]

@thebsdbox this is ready for review/merge. Thanks a lot!