Run tests against a later postgres version

People have had anecdotal success in the wild with versions up to and including Postgres 15, so this should be fine.

.github/workflows/pr_workflow.yml

@@ -10,7 +10,7 @@ jobs:
     runs-on: ubuntu-latest
     services:
       postgres:
-        image: postgres:9.6
+        image: postgres:15
         env:
           POSTGRES_PASSWORD: postgres
         options: >-

.github/workflows/release.yml

@@ -19,7 +19,7 @@ jobs:
     runs-on: ubuntu-latest
     services:
       postgres:
-        image: postgres:9.6
+        image: postgres:15
         env:
           POSTGRES_PASSWORD: postgres
         options: >-

.github/workflows/test_and_build.yml

@@ -13,7 +13,7 @@ jobs:
     runs-on: ubuntu-latest
     services:
       postgres:
-        image: postgres:9.6
+        image: postgres:15
         env:
           POSTGRES_PASSWORD: postgres
         options: >-
@@ -44,7 +44,7 @@ jobs:
     runs-on: ubuntu-latest
     services:
       postgres:
-        image: postgres:9.6
+        image: postgres:15
         env:
           POSTGRES_PASSWORD: postgres
         options: >-

docs/Configure.md

@@ -1,6 +1,6 @@
 # GoCD Analytics Plugin
 
-This plugin requires an **empty** PostgreSQL database for its data. If you are using the GoCD with PostgreSQL as the database backend, please note that the database schema that you use for analytics data should be separate from the schema used by GoCD. It is recommended that you use PostgreSQL versions 9.6.
+This plugin requires an **empty** PostgreSQL database for its data. If you are using the GoCD with PostgreSQL as the database backend, please note that the database schema that you use for analytics data should be separate from the schema used by GoCD. This plugin was most rigorously tested years ago against PostgreSQL 9.6, however later versions appear to work fine.
 
 Once you've installed the plugin and started the GoCD server, you can provide it with the credentials of your PostgreSQL database. To do this:
 

docs/Install.md

@@ -54,11 +54,11 @@ $ cd /var/lib/go-server/; tree .
 
 ### PostgreSQL
 
-- This plugin requires PostgreSQL `v9.6`.
+- This plugin requires PostgreSQL `v9.6`+.
 
 - This plugin requires an **empty** PostgreSQL database for its data. If you are using the GoCD PostgreSQL Addon, please note that the database schema that you use for analytics data should be separate from the schema used by GoCD.
 
-- The plugin requires the [citext module](https://www.postgresql.org/docs/9.6/static/citext.html) for creating the schema. Install the `postgresql-contrib` packages to include the citext module.
+- The plugin requires the [citext module](https://www.postgresql.org/docs/current/citext.html) for creating the schema. Install the `postgresql-contrib` packages to include the citext module.
 
 - **Creating the citext extension:**