Prevent remaining defaults from being evaluated as string 'None'

postgres/defaults.yaml

@@ -32,8 +32,8 @@ postgres:
       url: https://github.com/PostgresApp/PostgresApp/releases/download/v2.1.1/Postgres-2.1.1.dmg
       sum: sha256=ac0656b522a58fd337931313f09509c09610c4a6078fe0b8e469e69af1e1750b
     homebrew:
-      url:
-      sum:
+      url: ''
+      sum: ''
     dl:
       opts: -s -L
       interval: 60
@@ -67,4 +67,4 @@ postgres:
 
   linux:
     #Alternatives system are disabled by a 'altpriority=0' pillar.
-    altpriority:
+    altpriority: 0