Upgrade all default Postgres versions. (#22)

Author: fergusstrange

config.go

@@ -107,9 +107,9 @@ type PostgresVersion string
 
 // Predefined supported Postgres versions.
 const (
-	V13 = PostgresVersion("13.1.0")
-	V12 = PostgresVersion("12.1.0-1")
-	V11 = PostgresVersion("11.6.0-1")
-	V10 = PostgresVersion("10.11.0-1")
-	V9  = PostgresVersion("9.6.16-1")
+	V13 = PostgresVersion("13.2.0")
+	V12 = PostgresVersion("12.6.0")
+	V11 = PostgresVersion("11.11.0")
+	V10 = PostgresVersion("10.16.0")
+	V9  = PostgresVersion("9.6.21")
 )