Fix misspelled PostgreSQL

Author: jboxman

modules/templates-rails-creating-database-service.adoc

@@ -4,7 +4,7 @@
 [id="templates-rails-creating-database-service_{context}"]
 = Creating the database service
 
-Your Rails application expects a running database service. For this service use PostgeSQL database image.
+Your Rails application expects a running database service. For this service use PostgreSQL database image.
 
 To create the database service, use the `oc new-app` command. To this command you must pass some necessary environment variables which are used inside the database container. These environment variables are required to set the username, password, and name of the database. You can change the values of these environment variables to anything you would like. The variables are as follows: