Fix postgres tests

Tests were failing on CI with postgres due to an error with the
username.

Author: AlistairNorman

bin/dummy-app

@@ -30,6 +30,16 @@ fi
 
 cd ./dummy-app
 
+if [ -n "$DB_HOST" ]; then
+  echo "~~~> Configuring database.yml for DB_HOST=$DB_HOST"
+  ruby -i -pe '
+    if $_ =~ /^  (pool|max_connections):/
+      $_ += "  host: <%= ENV.fetch(\"DB_HOST\", \"localhost\") %>\n"
+      $_ += "  username: <%= ENV[\"DB_USERNAME\"] %>\n"
+    end
+  ' config/database.yml
+fi
+
 echo "Generating manifest file"
 mkdir -p app/assets/config
 cat <<MANIFESTJS > app/assets/config/manifest.js