Helm-Toolkit: Add a function to return quoted csv sting from a list

Added a utility function of return joint list with single quotes and
separated with comma.

Change-Id: I815404a30e0021b938b2857d1eaf0ea4cb8927c9

helm-toolkit/templates/utils/_joinListWithCommaAndSingleQuotes.tpl

@@ -0,0 +1,34 @@
+{{/*
+Copyright 2017 The Openstack-Helm Authors.
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+   http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+*/}}
+
+{{/*
+abstract: |
+  Joins a list of values into a comma seperated string with single quotes
+  around each value.
+values: |
+  test:
+    - foo
+    - bar
+usage: |
+  {{ include "helm-toolkit.utils.joinListWithCommaAndSingleQuotes" .Values.test }}
+return: |
+  'foo','bar'
+*/}}
+
+{{- define "helm-toolkit.utils.joinListWithCommaAndSingleQuotes" -}}
+{{- $local := dict "first" true -}}
+{{- range $k, $v := . -}}{{- if not $local.first -}},{{- end -}}'{{- $v -}}'{{- $_ := set $local "first" false -}}{{- end -}}
+{{- end -}}