WIFI-1238 set all imagePullPolicies to Always (#38)

* set all imagePullPolicies to Always
* use chart-level and global image pull policy
* make images configurable

tip-wlan/charts/postgresql/templates/tests/test-postgres-record-insert-del.yaml

@@ -12,6 +12,7 @@ spec:
   containers:
   - name: {{ include "common.name" . }}-test-postgres-basic
     image: {{ template "postgresql.image" . }}
+    imagePullPolicy: {{ .Values.image.pullPolicy | default .Values.global.pullPolicy }} 
     env:
       - name: POSTGRES_USER
         value: {{ include "postgresql.username" . | quote }}

tip-wlan/charts/postgresql/values.yaml

@@ -22,7 +22,7 @@ image:
   ## Defaults to 'Always' if image tag is 'latest', else set to 'IfNotPresent'
   ## ref: http://kubernetes.io/docs/user-guide/images/#pre-pulling-images
   ##
-  pullPolicy: IfNotPresent
+  pullPolicy: Always
   ## Optionally specify an array of imagePullSecrets.
   ## Secrets must be manually created in the namespace.
   ## ref: https://kubernetes.io/docs/tasks/configure-pod-container/pull-image-private-registry/