Make postgresVersion Helm variable required

This avoids some messiness that could occur on upgrades if this
value is just a default, as one must explicitly set the value.

Author: Jonathan S. Katz

helm/postgres/templates/postgres.yaml

@@ -3,7 +3,7 @@ kind: PostgresCluster
 metadata:
   name: {{ default .Release.Name .Values.name }}
 spec:
-  postgresVersion: {{ default 13 .Values.postgresVersion }}
+  postgresVersion: {{ required "You must set the version of Postgres to deploy." .Values.postgresVersion }}
   {{- if .Values.postGISVersion }}
   postGISVersion: {{ quote .Values.postGISVersion }}
   {{- end }}

helm/postgres/values.yaml

@@ -14,8 +14,8 @@
 # postgresVersion sets the version to deploy. This version number needs to be
 # available as one of the "RELATED_IMAGE_POSTGRES_..." images as part of the PGO
 # installation if you want to deploy the image without setting the "postgres"
-# image variable. This defaults to the below value.
-# postgresVersion: 13
+# image variable. This value is required.
+postgresVersion: 14
 
 # postGISVersion if sets and coupled with a PostGIS enabled container, enables
 # PostGIS. This version number needs to be available as one of the